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Editor’s Choice Articles

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

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14 pages, 3241 KiB  
Article
Modeling the Effect of Ionospheric Electron Density Profile and Its Inhomogeneities on Sprite Halos
by Jinbo Zhang, Jiawei Niu, Zhibin Xie, Yajun Wang, Xiaolong Li and Qilin Zhang
Atmosphere 2024, 15(10), 1169; https://doi.org/10.3390/atmos15101169 - 30 Sep 2024
Viewed by 465
Abstract
Sprite halos are diffuse glow discharges in the D-region ionosphere triggered by the quasi-electrostatic (QES) fields of lightning discharges. A three-dimensional (3D) QES model is adopted to investigate the effect of ionospheric electron density on sprite halos. The electron density is described by [...] Read more.
Sprite halos are diffuse glow discharges in the D-region ionosphere triggered by the quasi-electrostatic (QES) fields of lightning discharges. A three-dimensional (3D) QES model is adopted to investigate the effect of ionospheric electron density on sprite halos. The electron density is described by an exponential formula, parameterized by reference height (h’) and sharpness (β), and the local inhomogeneity has a Gaussian density distribution. Simulation results indicate that the reference height and steepness of the nighttime electron density affect the penetration altitudes and amplitudes of normalized electric fields, as well as the altitudes and intensities of the corresponding sprite halos optical emissions. A comparison of the daytime and nighttime conditions demonstrates that the daytime electron density profile is not favorable for generating sprite halos emissions. Furthermore, the pre-existing electron density inhomogeneities lead to enhanced local electric fields and optical emissions, potentially offering a plausible explanation for the horizontal displacement between sprites and their parent lightning, as well as their clustering. Full article
(This article belongs to the Special Issue Impact of Thunderstorms on the Upper Atmosphere)
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10 pages, 5879 KiB  
Technical Note
Assessing Downburst Kinematics Using Video Footage Analysis
by Djordje Romanic and Lalita Allard Vavatsikos
Atmosphere 2024, 15(10), 1168; https://doi.org/10.3390/atmos15101168 - 30 Sep 2024
Viewed by 754
Abstract
Measurements of downburst outflows using standard meteorological instruments (e.g., anemometers) are rare due to their transient and localized nature. However, video recordings of such events are becoming more frequent. This short communication (Technical Note) study presents a new approach to estimating the kinematics [...] Read more.
Measurements of downburst outflows using standard meteorological instruments (e.g., anemometers) are rare due to their transient and localized nature. However, video recordings of such events are becoming more frequent. This short communication (Technical Note) study presents a new approach to estimating the kinematics of a downburst event using video footage recordings of the event. The main geometric dimensions of the event, such as downdraft diameter, cloud base height, outflow depth, and the radius of the outflow at a given moment in time, are estimated by sizing them against reference structures of known dimensions that are present in the video footage. From this analysis, and knowing the frame rate of the video recording, one can estimate the characteristic velocities in the downburst event, such as the mean downdraft velocity and the mean velocity of the radial outflow propagation. The proposed method is tested on an August 2015 downburst event that hit Tucson, Arizona, United States. The diameter of the downburst outflow increased with the time from approximately 1.10 km to 3.35 km. This range of values indicates that the event was a microburst. The mean descending velocity of downburst downdraft was 8.9 m s−1 and the horizontal velocity of outflow propagation was 17.7 m s−1. The latter velocity is similar to the measured wind gust at the nearby weather station and Doppler radar. The outflow depth is estimated at 160 m, and the cloud base height was approximately 1.24 km. Estimating the kinematics of downbursts using video footage, while subject to certain limitations, does yield a useful estimation of the main downburst kinematics that contribute to a better quantification of these localized windstorms. Full article
(This article belongs to the Section Meteorology)
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16 pages, 1624 KiB  
Article
Concurrent Particulate Matter and Heat Exposure in Working and Non-Working Women in Rural Guatemala
by Jaime Butler-Dawson, Grant Erlandson, Diana Jaramillo, Laura Calvimontes, Daniel Pilloni, James Seidel, Colton Castro, Karely Villarreal Hernandez, Lyndsay Krisher, Stephen Brindley, Miranda Dally, Alex Cruz, Katherine A. James, Lee S. Newman, Joshua W. Schaeffer and John L. Adgate
Atmosphere 2024, 15(10), 1175; https://doi.org/10.3390/atmos15101175 - 30 Sep 2024
Viewed by 580
Abstract
High temperatures and air pollution exposure are individually known risks to human health, with amplifying adverse health effects during periods of co-exposure. This study compared co-occurring individual-level exposures to particulate matter (PM5, aerodynamic diameter of ≤5 μm) and heat among women [...] Read more.
High temperatures and air pollution exposure are individually known risks to human health, with amplifying adverse health effects during periods of co-exposure. This study compared co-occurring individual-level exposures to particulate matter (PM5, aerodynamic diameter of ≤5 μm) and heat among women in residential and agricultural settings in Guatemala. We measured personal and ambient exposure to PM5, temperature, and humidity among 21 female sugarcane workers in the fields and on their off days. We measured similar exposures among a group of 30 community members not involved in sugarcane work. We collected 171 personal PM5 measurements across 18 sampling days. The median workday personal PM5 concentration was 271 µg/m3, which was 3.6-fold higher than ambient area levels in the fields. The median personal PM5 concentration was 95.8 µg/m3 for off-work days and 83.5 µg/m3 for community days. The average workday individual-level temperature and humidity were 39.4 °C and 82.4%, respectively, with significantly lower temperatures on off-work and community days. The women workers and community members were exposed to high levels of PM5 and heat in both occupational and residential settings. Research needs to consider individual-level exposures at both work and home to help tailor more effective comprehensive prevention efforts to reduce risks. Full article
(This article belongs to the Special Issue Climate Change and Health: Enhancing Coherence of the Knowledge Base, Policies and Strategies into a Healthy, Sustainable and Resilient Future (2nd Edition))
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18 pages, 1578 KiB  
Review
The Generation of Seismogenic Anomalous Electric Fields in the Lower Atmosphere, and Its Application to Very-High-Frequency and Very-Low-Frequency/Low-Frequency Emissions: A Review
by Masashi Hayakawa, Yasuhide Hobara, Koichiro Michimoto and Alexander P. Nickolaenko
Atmosphere 2024, 15(10), 1173; https://doi.org/10.3390/atmos15101173 - 30 Sep 2024
Viewed by 496
Abstract
The purpose of this paper is, first of all, to review the previous works on the seismic (or earthquake (EQ)-related) direct current (DC) (or quasi-stationary) electric fields in the lower atmosphere, which is likely to be generated by the conductivity current flowing in [...] Read more.
The purpose of this paper is, first of all, to review the previous works on the seismic (or earthquake (EQ)-related) direct current (DC) (or quasi-stationary) electric fields in the lower atmosphere, which is likely to be generated by the conductivity current flowing in the closed atmosphere–ionosphere electric circuit during the preparation phase of an EQ. The current source is electromotive force (EMF) caused by upward convective transport and the gravitational sedimentation of radon and charged aerosols injected into the atmosphere by soil gasses during the course of the intensification of seismic processes. The theoretical calculations predict that pre-EQ DC electric field enhancement in the atmosphere can reach the breakdown value at the altitudes 2–6 km, suggesting the generation of a peculiar seismic-related thundercloud. Then, we propose to apply this theoretical inference to the observational results of seismogenic VHF (very high frequency) and VLF/LF (very low frequency/low frequency) natural radio emissions. The formation of such a peculiar layer initiates numerous chaotic electrical discharges within this region, leading to the generation of VHF electromagnetic radiation. Earlier works on VHF seismogenic radiation performed in Greece have been compared with the theoretical estimates, and showed a good agreement in the frequency range and intensity. The same idea can also be applied, for the first time, to seismogenic VLF/LF lightning discharges, which is completely the same mechanism with conventional cloud-to-ground lightning discharges. In fact, such seismogenic VLF/LF lightning discharges have been observed to appear before an EQ. So, we conclude in this review that both seismogenic VHF radiation and VLF/LF lightning discharges are regarded as indirect evidence of the generation of anomalous electric fields in the lowest atmosphere due to the emanation of radioactive radon and charged aerosols during the preparation phase of EQs. Finally, we have addressed the most fundamental issue of whether VHF and VLF/LF radiation reported in earlier works is either of atmospheric origin (as proposed in this paper) or of lithospheric origin as the result of microfracturing in the EQ fault region, which has long been hypothesized. This paper will raise a question regarding this hypothesis of lithospheric origin by proposing an alternative atmospheric origin outlined in this review. Also, the data on seismogenic electromagnetic radiation and its inference on perturbations in the lower atmosphere will be suggested to be extensively integrated in future lithosphere–atmosphere–ionosphere coupling (LAIC) studies. Full article
(This article belongs to the Section Upper Atmosphere)
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18 pages, 6020 KiB  
Article
Variation in the Quanta-to-Energy Ratio of Photosynthetically Active Radiation under the Cloudless Atmosphere
by Weibo Wang, Shangzhan Cai, Jiang Huang, Rui Ding and Lei Chen
Atmosphere 2024, 15(10), 1166; https://doi.org/10.3390/atmos15101166 - 29 Sep 2024
Viewed by 528
Abstract
The quanta-to-energy ratio plays a crucial role in converting energy units to quantum units in the context of photosynthetically active radiation (PAR). Despite its widespread use, the effects of atmospheric particles and solar zenith angle (SZA) on the quanta-to-energy ratio remain unclear. In [...] Read more.
The quanta-to-energy ratio plays a crucial role in converting energy units to quantum units in the context of photosynthetically active radiation (PAR). Despite its widespread use, the effects of atmospheric particles and solar zenith angle (SZA) on the quanta-to-energy ratio remain unclear. In this study, both simulation and observation data revealed that the principal wavelength, which can be transformed into the quanta-to-energy ratio using a constant, exhibits a slow initial growth, followed by a rapid increase beyond 60° solar zenith angles and a subsequent dramatic decrease after reaching its maximum value. The measured quanta-to-energy ratio demonstrates a variable range of less than 3% for SZA under 70° in a cloudless atmosphere, with significant changes only occurring at zenith angles above 80°. Simulation data indicate that ozone, wind speed, surface-level pressure, surface air temperature, and relative humidity have negligible effects on the quanta-to-energy ratio. The Ångstrom exponent exerts a minor influence on the quanta-to-energy ratio by affecting diffuse radiation. Visibility, however, is found to have a substantial impact on the quanta-to-energy ratio. As a result, two relationships are established, linking the principal wavelength to visibility and the diffuse fraction of PAR. The principal wavelength serves as an effective measure of solar spectrum variability, remaining unaffected by radiation energy. This implies that atmospheric parameters which do not alter the solar spectrum will not influence the principal wavelength. The strong correlations between the principal wavelength, visibility, and the diffuse fraction of PAR suggest a broader range of applications for the principal wavelength in various research domains, opening up new avenues for exploration and potential contributions to numerous fields. Full article
(This article belongs to the Section Meteorology)
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10 pages, 918 KiB  
Article
Salix humboldtiana as an Indicator of Air Pollution by Trace Metals in the Urban Areas of the City of Loja, Southern Ecuador
by Ángel Benítez, Diego Ordóñez and James Calva
Atmosphere 2024, 15(10), 1160; https://doi.org/10.3390/atmos15101160 - 28 Sep 2024
Viewed by 588
Abstract
Air pollution is the most important environmental problem in urban areas related to vehicular traffic and industrial activities. The widespread presence of common urban trees, such as Salix humboldtiana, and their ability to tolerate diverse environmental conditions make this species an especially [...] Read more.
Air pollution is the most important environmental problem in urban areas related to vehicular traffic and industrial activities. The widespread presence of common urban trees, such as Salix humboldtiana, and their ability to tolerate diverse environmental conditions make this species an especially promising candidate for assessing environmental metal contamination. Therefore, biomonitoring with vascular plants has been widely used to assess air pollution, especially the accumulation of trace metal concentrations. Therefore, for the first time, we analyzed the concentration of trace metals using Salix humboldtiana in twelve areas with different levels of pollution in a city in Southern Ecuador. For this purpose, samples were taken from each site to assess the accumulation of trace metals such as Zn, Mn, Fe, Cd, Cr, Pb, Cu, Al, and Ni. The results obtained showed significant differences in the concentrations of Zn, Mn, Fe, and Cd between the urban areas and the control area, indicating that the central areas were the most polluted by vehicular traffic. However, these findings suggest that Salix humboldtiana may not be a particularly effective tool for quantifying levels of environmental metal contamination such as Cu and Ni, at least in urban areas in the city of Loja. This study has demonstrated that Salix humboldtiana leaves can effectively monitor trace metals associated with road traffic emissions in areas with varying levels of vehicular activity, indicating that vascular plants can be utilized for this purpose in tropical cities. Full article
(This article belongs to the Special Issue Bioindicators in Air Pollution Monitoring)
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10 pages, 8370 KiB  
Article
Ozone Induces Oxidative Stress and Inflammation in Nasal Mucosa of Rats
by Yu Zhan, Lufang Tian, Ruxin Zhang, Shaoqing Yu and Na Sun
Atmosphere 2024, 15(10), 1148; https://doi.org/10.3390/atmos15101148 - 25 Sep 2024
Viewed by 488
Abstract
Background: The development of the global economy has led to changes in air pollution patterns. The haze phenomenon characterized by high concentrations of particulate matter 2.5 (PM2.5) has changed to complex pollution, and photochemical pollution characterized by ozone (O3) has [...] Read more.
Background: The development of the global economy has led to changes in air pollution patterns. The haze phenomenon characterized by high concentrations of particulate matter 2.5 (PM2.5) has changed to complex pollution, and photochemical pollution characterized by ozone (O3) has become increasingly prominent. Ozone pollution and its impact on human health has become an important topic that needs to be studied urgently. Objective: To investigate the effects of ozone on oxidative stress and inflammation in the nasal mucosa of a rat model. Methods: Thirty-two healthy female Sprague–Dawley rats, eight in each group, were divided into four groups using the randomized numeric table method: normal control group (NC group), normal rats with a low level of ozone inhalation exposure (NEL group, 0.5 ppm), medium ozone inhalation exposure (NEM group, 1 ppm), and high ozone inhalation exposure (NEH group, 2 ppm). The ozone inhalation exposure groups were placed in the ozone inhalation exposure system and exposed to different concentrations of ozone for 2 h each day for 6 weeks. Nasal secretion was measured, and nasal lavage and nasal mucosa were collected. Malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities were measured by colorimetric assay, and the nasal mucosa was analyzed by Western blot. Western blot (WB) was used to detect the expression of NF-κB p65 nuclear protein in nasal mucosa. The mRNA expression of NF-κB target genes IL-6 and IL-8 and tumor necrosis factor-α (TNF-α) was detected by real-time quantitative PCR (qRT-PCR), and the protein content of pro-inflammatory factors IL-6, IL-8, and TNF-α was detected by ELISA in serum and nasal lavage fluid. The nasal mucosa of rats was stained with hematoxylin-eosin (HE) to observe the pathological changes in the nasal mucosa. The data were analyzed by SPSS 20.0 software. Results: The amount of nasal secretion increased significantly in all groups after ozone exposure compared with that in the NC group. The MDA content of the nasal mucosa was significantly increased in the ozone-exposed group compared with the NC group, and the activity levels of SOD and GSH-Px in the nasal mucosa were lower in the ozone-exposed group than in the NC group. The mRNA expression of IL-6, IL-8, and TNF-α in the nasal mucosa of the ozone-exposed group was elevated, and the protein content of TNF-α, IL-6, and IL-8 in the nasal lavage fluid was elevated, and the content increased with the increase in ozone concentration. The expression of NF-κB p65 intracellular protein in the nasal mucosa of each ozone-exposed group was higher than that of the normal group, and the content increased with the increase in ozone concentration. Conclusions: Ozone inhalation exposure promotes oxidative stress and the release of inflammatory factors TNF-α, IL-6, and IL-8, leading to pathological damage of the nasal mucosa, the degree of which increases with increasing concentration. This pathological process may be related to the activation of the transcription factor NF-κB by ozone in the nasal mucosa of rats, which increases the expression of its target genes. Full article
(This article belongs to the Special Issue Climate Change, Air Pollution and Human Health: Past, Present and Future)
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19 pages, 17434 KiB  
Article
Impact of Lockdowns on Air Pollution: Case Studies of Two Periods in 2022 in Guangzhou, China
by Xinlei Zhao, Xian-Xiang Li, Rui Xin, Yuejuan Zhang and Chun-Ho Liu
Atmosphere 2024, 15(9), 1144; https://doi.org/10.3390/atmos15091144 - 23 Sep 2024
Viewed by 745
Abstract
The photochemical mechanisms of ozone (O3) formation are complex, and simply reducing nitrogen oxide (NOx) emissions is insufficient to reduce O3 concentrations. The lockdown due to the Coronavirus Disease 2019 (COVID-19) pandemic provided a rare opportunity to explore [...] Read more.
The photochemical mechanisms of ozone (O3) formation are complex, and simply reducing nitrogen oxide (NOx) emissions is insufficient to reduce O3 concentrations. The lockdown due to the Coronavirus Disease 2019 (COVID-19) pandemic provided a rare opportunity to explore the mechanisms of O3 formation and evaluate the performance of NOx emission control strategies through practical observations. This study integrates data from ground stations with observations from the TROPOMI sensor on the Sentinel-5P satellite to analyze air quality changes during the two one-month lockdown periods in Guangzhou, China, in March and November 2022. Our analysis particularly focuses on the impact of these lockdowns on O3 and NO2 concentrations, along with shifts in the sensitivity of ozone formation. Furthermore, we have assessed concentration changes of four major pollutants: PM2.5, PM10, SO2, and CO. The results show that the average O3 concentration in Guangzhou decreased during the March lockdown, while the average O3 concentration at three stations in the western part of Guangzhou increased during the November lockdown. The western part of Guangzhou is a VOCs (volatile organic compounds)-limited zone, and the NO2 emission reduction from the lockdown reduced the titration effect on O3, which led to the increase in O3 concentration. Overall, the impact of COVID-19 lockdowns on O3 concentrations depended on the local O3 producing sensitive system, and emissions of other major pollutants were reduced substantially, as reported in many other cities around the world. Full article
(This article belongs to the Section Air Quality)
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16 pages, 7416 KiB  
Article
Analysis of the Relationship between Upper-Level Aircraft Turbulence and the East Asian Westerly Jet Stream
by Kenan Li, Xi Chen, Liman A, Kaijun Wu, Haiwen Liu, Fengjing Dai, Tiantian Yang, Jia Yu and Kehua Wang
Atmosphere 2024, 15(9), 1138; https://doi.org/10.3390/atmos15091138 - 20 Sep 2024
Viewed by 640
Abstract
The jet stream is a primary factor contributing to turbulence, especially for upper-level aircraft. This study utilized pilot reports and ERA5 data from 2023 to investigate the relationship between upper-level turbulence and the East Asian westerly jet (EAJ). The results indicate that approximately [...] Read more.
The jet stream is a primary factor contributing to turbulence, especially for upper-level aircraft. This study utilized pilot reports and ERA5 data from 2023 to investigate the relationship between upper-level turbulence and the East Asian westerly jet (EAJ). The results indicate that approximately 45.9% of upper-level aircraft turbulence occurs within the jet stream, with the lowest proportion in August and the highest in January. Additionally, the strongest vertical wind shear (VMS) is found concentrated in the lower part of the jet stream core, particularly in the South–Down part of the jet stream, where upper-level aircraft turbulence occurs most frequently (27.1%). The most turbulent area is located between 30–40° N and 110–120° E, with the main air routes experiencing turbulence being the Henan sections of G212 and B208. From a seasonal perspective, there is less frequent occurrence of upper-level aircraft turbulence in summer and autumn but more in winter and spring. The EAJ volume increases with the strengthening of the jet core wind speed, with the jet core regions being most distinct at altitudes of 200~300 hPa. Meanwhile, the jet stream intensity index peaks at 70.6 m/s in January and reaches its lowest value of 7.1 m/s in August. The jet stream axis shifts southward in winter and northward in summer, reaching the southernmost position in December at 32.2° N and the northernmost position in August at 43.5° N. Furthermore, the VMS at turbulence points within the jet stream is higher than that at the turbulence points outside the jet stream, and the Richardson number (RI) is lower. Moreover, the temporal distribution of upper-level aircraft turbulence is primarily determined by the location and intensity of the jet stream, of which the jet stream intensity index provides guidance and thus serves as a reliable indicator. Full article
(This article belongs to the Special Issue Observations and Analysis of Upper Atmosphere)
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21 pages, 1517 KiB  
Article
Global Health Emergencies of Extreme Drought Events: Historical Impacts and Future Preparedness
by Zakaria A. Mani, Amir Khorram-Manesh and Krzysztof Goniewicz
Atmosphere 2024, 15(9), 1137; https://doi.org/10.3390/atmos15091137 - 20 Sep 2024
Cited by 1 | Viewed by 1451
Abstract
This study examines the global health implications of extreme drought events from 2000 to 2023. Utilizing data from the International Disaster Database (EM-DAT), we analyzed the number of people affected and the total deaths attributed to drought. Our findings reveal that over 1.6 [...] Read more.
This study examines the global health implications of extreme drought events from 2000 to 2023. Utilizing data from the International Disaster Database (EM-DAT), we analyzed the number of people affected and the total deaths attributed to drought. Our findings reveal that over 1.6 billion people have been impacted by drought globally, with Southern Asia and Sub-Saharan Africa being the most severely affected regions. India and China account for a significant portion of the affected population, with 688.2 million and 327.35 million impacted people, respectively. Drought-related mortality has also been substantial, with over 24,000 deaths recorded globally, including more than 20,000 in Somalia alone. The study highlights the uneven distribution of drought impacts, underscoring the need for targeted interventions and comprehensive drought preparedness strategies. Our analysis also reveals the critical role of socio-economic factors in exacerbating the health impacts of drought, particularly in regions with inadequate healthcare infrastructure and limited access to resources. This study provides novel insights into the specific health impacts of drought, including the correlation between drought frequency and mortality rates, and offers actionable recommendations for improving future emergency responses and health system preparedness. These recommendations are tailored to address the unique challenges faced by the most vulnerable regions, emphasizing the importance of context-specific strategies to enhance resilience against the growing threat of climate-induced droughts. Full article
(This article belongs to the Special Issue Climate Change and Extreme Weather Disaster Risks)
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12 pages, 3994 KiB  
Article
Possible Identification of Precursor ELF Signals on Recent EQs That Occurred Close to the Recording Station
by Ioannis Contopoulos, Janusz Mlynarczyk, Jerzy Kubisz and Vasilis Tritakis
Atmosphere 2024, 15(9), 1134; https://doi.org/10.3390/atmos15091134 - 19 Sep 2024
Viewed by 610
Abstract
The Lithospheric–Atmospheric–Ionospheric Coupling (LAIC) mechanism stands as the leading model for the prediction of seismic activities. It consists of a cascade of physical processes that are initiated days before a major earthquake. The onset is marked by the discharge of ionized gases, such [...] Read more.
The Lithospheric–Atmospheric–Ionospheric Coupling (LAIC) mechanism stands as the leading model for the prediction of seismic activities. It consists of a cascade of physical processes that are initiated days before a major earthquake. The onset is marked by the discharge of ionized gases, such as radon, through subterranean fissures that develop in the lead-up to the quake. This discharge augments the ionization at the lower atmospheric layers, instigating disturbances that extend from the Earth’s surface to the lower ionosphere. A critical component of the LAIC sequence involves the distinctive perturbations of Extremely Low Electromagnetic Frequencies (ELF) within the Schumann Resonances (SR) spectrum of 2 to 50 Hz, detectable days ahead of the seismic event. Our study examines 10 earthquakes that transpired over a span of 3.5 months—averaging nearly three quakes monthly—which concurrently generated 45 discernible potential precursor seismic signals. Notably, each earthquake originated in Southern Greece, within a radius of 30 to 250 km from the observatory on Mount Parnon. Our research seeks to resolve two important issues. The first concerns the association between specific ELF signals and individual earthquakes—a question of significant importance in seismogenic regions like Greece, where earthquakes occur frequently. The second inquiry concerns the parameters that determine the detectability of an earthquake by a given station, including the requisite proximity and magnitude. Initial findings suggest that SR signals can be reliably linked to a particular earthquake if the observatory is situated within the earthquake’s preparatory zone. Conversely, outside this zone, the correlation becomes indeterminate. Additionally, we observe a differentiation in SR signals based on whether the earthquake took place over land or offshore. The latter category exhibits unique signal behaviors, potentially attributable to the water layers above the epicenter acting as a barrier to the ascending gases, thereby affecting the atmospheric–ionospheric ionization process. Full article
(This article belongs to the Section Upper Atmosphere)
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16 pages, 2217 KiB  
Article
In-Vehicle Air Pollutant Exposures from Daily Commute in the San Francisco Bay Area, California
by Reshmasri Deevi and Mingming Lu
Atmosphere 2024, 15(9), 1130; https://doi.org/10.3390/atmos15091130 - 18 Sep 2024
Viewed by 840
Abstract
With urbanization and increased vehicle usage, understanding the exposure to air pollutants inside the vehicles is vital for developing strategies to mitigate associated health risks. In-vehicle air quality influences the comfort of the driver during long commutes and has gained significant interest. This [...] Read more.
With urbanization and increased vehicle usage, understanding the exposure to air pollutants inside the vehicles is vital for developing strategies to mitigate associated health risks. In-vehicle air quality influences the comfort of the driver during long commutes and has gained significant interest. This study focuses on studying in-vehicle air quality in the San Francisco Bay Area in California, an urban setting with significant traffic congestion and varied emission sources and road conditions. Each trip is about 80.5 km (50 miles) in length, with commute times of approximately one hour. Two low-cost portable sensors were employed to simultaneously measure in-vehicle pollutants (PM2.5, PM10, and CO2) during morning and evening rush hours from May 2023 to December 2023. Seasonally averaged PM2.5 varied from 5.07 µg/m3 to 6.55 µg/m3 during morning rush hours and from 4.38 µg/m3 to 4.47 µg/m3 during evening rush hours. In addition, the impacts of local PM2.5, vehicle ventilation settings, and speed of the vehicle on in-vehicle PM concentrations were also analyzed. CO2 buildup in vehicles was studied for two scenarios: one with inside recirculation enabled (RC on) and the other with circulation from outside (RC off). With RC off, CO2 concentrations are largely within the 1100 ppm range recommended by many organizations, while the average CO2 concentrations can be three times high under recirculation mode. This research suggests that low-cost sensors can provide valuable insights into the dynamics of air pollution in the in-vehicle microenvironment, which can better help commuters reduce health risks. Full article
(This article belongs to the Special Issue Recent Advances in Mobile Source Emissions (2nd Edition))
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26 pages, 357 KiB  
Review
Agricultural Drought Monitoring: A Comparative Review of Conventional and Satellite-Based Indices
by Ali Gholinia and Peyman Abbaszadeh
Atmosphere 2024, 15(9), 1129; https://doi.org/10.3390/atmos15091129 - 17 Sep 2024
Viewed by 1198
Abstract
Drought is a natural hazard that causes significant economic and human losses by creating a persistent lack of precipitation that impacts agriculture and hydrology. It has various characteristics, such as delayed effects and variability across dimensions like severity, spatial extent, and duration, making [...] Read more.
Drought is a natural hazard that causes significant economic and human losses by creating a persistent lack of precipitation that impacts agriculture and hydrology. It has various characteristics, such as delayed effects and variability across dimensions like severity, spatial extent, and duration, making it difficult to characterize. The agricultural sector is especially susceptible to drought, which is a primary cause of crop failures and poses a significant threat to global food security. To address these risks, it is crucial to develop effective methods for identifying, classifying, and monitoring agricultural drought, thereby aiding in planning and mitigation efforts. Researchers have developed various tools, including agricultural drought indices, to quantify severity levels and determine the onset and evolution of droughts. These tools help in early-stage forecasting and ongoing monitoring of drought conditions. The field has been significantly advanced by remote sensing technology, which now offers high-resolution spatial and temporal data, improving our capacity to monitor and assess agricultural drought. Despite these technological advancements, the unpredictable nature of environmental conditions continues to pose challenges in drought assessment. It remains essential to provide an overview of agricultural drought indices, incorporating both conventional methods and modern remote sensing-based indices used in drought monitoring and assessment. Full article
(This article belongs to the Special Issue Drought Impacts on Agriculture and Mitigation Measures)
18 pages, 1912 KiB  
Article
Tire Wear Emissions by Highways: Impact of Season and Surface Type
by Jason A. Miech, Saed Aker, Zhaobo Zhang, Hasan Ozer, Matthew P. Fraser and Pierre Herckes
Atmosphere 2024, 15(9), 1122; https://doi.org/10.3390/atmos15091122 - 15 Sep 2024
Viewed by 1089
Abstract
With the increasing number of electric vehicles taking to the roads, the impact of tailpipe emissions on air quality will decrease, while resuspended road dust and brake/tire wear will become more significant. This study quantified PM10 emissions from tire wear under a [...] Read more.
With the increasing number of electric vehicles taking to the roads, the impact of tailpipe emissions on air quality will decrease, while resuspended road dust and brake/tire wear will become more significant. This study quantified PM10 emissions from tire wear under a range of real highway conditions with measurements across different seasons and roadway surface types in Phoenix, Arizona. Tire wear was quantified in the sampled PM10 using benzothiazoles (vulcanization accelerators) as tire markers. The measured emission factors had a range of 0.005–0.22 mg km−1 veh−1 and are consistent with an earlier experimental study conducted in Phoenix. However, these results are lower than values typically found in the literature and values calculated from emissions models, such as MOVES (MOtor Vehicle Emission Simulator). We found no significant difference in tire wear PM10 emission factors for different surface types (asphalt vs. diamond grind concrete) but saw a significant decrease in the winter compared to the summer. Full article
(This article belongs to the Special Issue Particulate Matters in Ambient Air: Characteristics, Composition, and Sources)
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24 pages, 2008 KiB  
Review
A Review on the Arctic–Midlatitudes Connection: Interactive Impacts, Physical Mechanisms, and Nonstationary
by Shuoyi Ding, Xiaodan Chen, Xuanwen Zhang, Xiang Zhang and Peiqiang Xu
Atmosphere 2024, 15(9), 1115; https://doi.org/10.3390/atmos15091115 - 13 Sep 2024
Viewed by 747
Abstract
In light of the rapid Arctic warming and continuous reduction in Arctic Sea ice, the complex two-way Arctic–midlatitudes connection has become a focal point in recent climate research. In this paper, we review the current understanding of the interactive influence between midlatitude atmospheric [...] Read more.
In light of the rapid Arctic warming and continuous reduction in Arctic Sea ice, the complex two-way Arctic–midlatitudes connection has become a focal point in recent climate research. In this paper, we review the current understanding of the interactive influence between midlatitude atmospheric variability and Arctic Sea ice or thermal conditions on interannual timescales. As sea ice diminishes, in contrast to the Arctic warming (cooling) in boreal winter (summer), Eurasia and North America have experienced anomalously cold (warm) conditions and record snowfall (rainfall), forming an opposite oscillation between the Arctic and midlatitudes. Both statistical analyses and modeling studies have demonstrated the significant impacts of autumn–winter Arctic variations on winter midlatitude cooling, cold surges, and snowfall, as well as the potential contributions of spring–summer Arctic variations to midlatitude warming, heatwaves and rainfall, particularly focusing on the role of distinct regional sea ice. The possible physical processes can be categorized into tropospheric and stratospheric pathways, with the former encompassing the swirling jet stream, horizontally propagated Rossby waves, and transient eddy–mean flow interaction, and the latter manifested as anomalous vertical propagation of quasi-stationary planetary waves and associated downward control of stratospheric anomalies. In turn, atmospheric prevailing patterns in the midlatitudes also contribute to Arctic Sea ice or thermal condition anomalies by meridional energy transport. The Arctic–midlatitudes connection fluctuates over time and is influenced by multiple factors (e.g., continuous melting of climatological sea ice, different locations and magnitudes of sea ice anomalies, internal variability, and other external forcings), undoubtedly increasing the difficulty of mechanism studies and the uncertainty surrounding predictions of midlatitude weather and climate. In conclusion, we provide a succinct summary and offer suggestions for future research. Full article
(This article belongs to the Special Issue Arctic Atmosphere–Sea Ice Interaction and Impacts)
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12 pages, 2197 KiB  
Article
Risk Associations between Air Pollution Exposure and Cardiovascular Diseases: A Residential Retrospective Cohort Study
by Elisa Bustaffa, Cristina Mangia, Liliana Cori, Marco Cervino, Fabrizio Bianchi and Fabrizio Minichilli
Atmosphere 2024, 15(9), 1113; https://doi.org/10.3390/atmos15091113 - 13 Sep 2024
Viewed by 583
Abstract
The population of the Venafro Valley (Southern Italy) faces various type of air pollution problems (industrial facilities, traffic, and biomass combustion). To estimate exposure to various pollution sources, a multi-stage random forest model was used, integrating particulate matter (PM) data with satellite observations, [...] Read more.
The population of the Venafro Valley (Southern Italy) faces various type of air pollution problems (industrial facilities, traffic, and biomass combustion). To estimate exposure to various pollution sources, a multi-stage random forest model was used, integrating particulate matter (PM) data with satellite observations, land-use patterns, and meteorological information generating maps of PM2.5 concentration. Four distinct PM2.5 exposure categories were established using the quartile method. To assess the association between PM2.5 and cause-specific mortality and morbidity, a time-dependent and sex-specific Cox multiple regression analysis was conducted, adjusting for age classes. In addition, the hazard ratios were accompanied by a probability measure of the strength of the evidence toward a hypothesis of health risk associated with the exposure under study (1−p value). The whole cohort was exposed to PM2.5 annual levels exceeding the 5 µg/m3 limit recommended by the World Health Organization. Mortality excesses were observed in class 3 for both sexes for cardiac heart diseases. Excesses of cardiovascular diseases were observed for both sexes in class 3 and 4. The study highlights significant signals warranting mitigation actions, which regional authorities are currently considering. Full article
(This article belongs to the Special Issue Research on Air Pollution and Human Exposures)
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27 pages, 14463 KiB  
Article
Numerical Investigation of Track and Intensity Evolution of Typhoon Doksuri (2023)
by Dieu-Hong Vu, Ching-Yuang Huang and Thi-Chinh Nguyen
Atmosphere 2024, 15(9), 1105; https://doi.org/10.3390/atmos15091105 - 11 Sep 2024
Viewed by 645
Abstract
This study utilized the WRF model to investigate the track evolution and rapid intensification (RI) of Typhoon Doksuri (2023) as it moved across the Luzon Strait and through the South China Sea (SCS). The simulation results indicate that Doksuri has a smaller track [...] Read more.
This study utilized the WRF model to investigate the track evolution and rapid intensification (RI) of Typhoon Doksuri (2023) as it moved across the Luzon Strait and through the South China Sea (SCS). The simulation results indicate that Doksuri has a smaller track sensitivity to the use of different physics schemes, while having a greater intensity sensitivity. Sensitivity numerical experiments with different physics schemes can well capture its northwestward movement in the first two days, but they predict less westward track deflection as the typhoon moves across the Luzon Strait and through the SCS. Moreover, all the experiments successfully simulated Doksuri’s RI, albeit with quite different rates and a time lag of 12 h. Among different combinations of physics schemes, there exists an optimal set of cumulus parameterization and cloud microphysics schemes for track and intensity predictions. Doksuri’s track changes as the typhoon moved across the Luzon Strait and through the SCS were influenced by the topographic effects of the terrain of the Philippines and Taiwan, to different extents. The track changes of Doksuri are explained by the wavenumber-one potential vorticity (PV) tendency budget from different physical processes, highlighting that the horizontal PV advection dominates the PV tendency throughout most of the simulation time due to the offset of vertical PV advection and differential diabatic heating. In addition, this study applies the extended Sawyer–Eliassen (SE) equation to compare the transverse circulations of the typhoon induced by various forcing sources. The SE solution indicates that radial inflow was largely driven in the lower-tropospheric vortex by strong diabatic heating, while being significantly enhanced in the lower boundary layer due to turbulent friction. All other physical forcing terms were relatively insignificant for the induced transverse circulation. The coordinated radial inflow at low levels may have led to the eyewall development in unbalanced dynamics. Intense diabatic heating thus was vital to the severe RI of Doksuri under a weak vertical wind shear. Full article
(This article belongs to the Special Issue Typhoon/Hurricane Dynamics and Prediction (2nd Edition))
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14 pages, 1319 KiB  
Article
Future Scenarios of Design Rainfall Due to Upcoming Climate Changes in NSW, Australia
by Iqbal Hossain, Shirley Gato-Trinidad, Monzur Imteaz and Scott Rayburg
Atmosphere 2024, 15(9), 1101; https://doi.org/10.3390/atmos15091101 - 10 Sep 2024
Viewed by 490
Abstract
The occurrence of rainfall is significantly affected by climate change around the world. While in some places this is likely to result in increases in rainfall, both winter and summer rainfall in most parts of New South Wales (NSW), Australia are projected to [...] Read more.
The occurrence of rainfall is significantly affected by climate change around the world. While in some places this is likely to result in increases in rainfall, both winter and summer rainfall in most parts of New South Wales (NSW), Australia are projected to decrease considerably due to climate change. This has the potential to impact on a range of hydraulic and hydrologic design considerations for water engineers, such as the design and construction of stormwater management systems. These systems are currently planned based on past extreme rain event data, and changes in extreme rainfall amounts due to climate change could lead to systems being seriously undersized (if extreme precipitation events become more common and/or higher in magnitude) or oversized (if extreme rainfall events become less frequent or decrease in magnitude). Both outcomes would have potentially serious consequences. Consequently, safe, efficient, and cost-effective urban drainage system design requires the consideration of impacts arising from climate change on the approximation of design rainfall. This study examines the impacts of climate change on the probability of occurrence of daily extreme rainfall in New South Wales (NSW), Australia. The analysis was performed for 29 selected meteorological stations located across NSW. Future design rainfall in this research was determined from the projected rainfall for different time periods (2020 to 2039, 2040 to 2059, 2060 to 2079, and 2080 to 2099). The results of this study show that design rainfall for the standard return periods was, in most cases, lower than that derived employing the design rainfall obtained from the Australian Bureau of Meteorology (BoM). While most of the analysed meteorological stations showed significantly different outcomes using the climate change scenario data, this varied considerably between stations and different time periods. This suggests that more work needs to be performed at the local scale to incorporate climate change predicted rainfall data into future stormwater system designs to ensure the best outcomes. Full article
(This article belongs to the Special Issue Statistical Approaches in Climatic Parameters Prediction)
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20 pages, 14248 KiB  
Article
A Stepwise Multifactor Regression Analysis of the Interactive Effects of Multiple Climate Factors on the Response of Vegetation Recovery to Drought
by Jingjing Fan, Yue Zhao, Dongnan Wang, Xiong Zhou, Yunyun Li, Wenwei Zhang, Fanfan Xu and Shibo Wei
Atmosphere 2024, 15(9), 1094; https://doi.org/10.3390/atmos15091094 - 8 Sep 2024
Viewed by 773
Abstract
In this study, a stepwise multifactor vegetation regression analysis (SMVRA) approach was proposed to investigate the interaction of multiple climate factors on vegetative growth in the study area from 2000 to 2020. It was developed by integrating the stepwise linear regression method, Standardized [...] Read more.
In this study, a stepwise multifactor vegetation regression analysis (SMVRA) approach was proposed to investigate the interaction of multiple climate factors on vegetative growth in the study area from 2000 to 2020. It was developed by integrating the stepwise linear regression method, Standardized Precipitation Evapotranspiration Index (SPEI), Normalized Difference Vegetation Index (NDVI), and Pearson correlation coefficient. SMVRA can be used to intuitively understand the interactive effects of multiple correlated factors (e.g., temperature, precipitation, potential evapotranspiration, and the drought index) upon vegetation. The results show that the resilience of vegetation in the BLR basin is influenced by the severity of drought. Annual changes in SPEI over the BLR basin show an increasing trend, with rates of 3.12 × 10−2. Precipitation and NDVI had a strong positive correlation (p < 0.05), found for 34.93% of the total pixels in the study area. In the BLR basin, vegetation growth is inhibited in the 4 years following a drought event. The area near 800 m is most sensitive to drought events. It provides a theoretical basis for future drought response and effective vegetation restoration in the region. Full article
(This article belongs to the Section Climatology)
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19 pages, 4999 KiB  
Article
Study on Downscaling Correction of Near-Surface Wind Speed Grid Forecasts in Complex Terrain
by Xin Liu, Zhimin Li and Yanbo Shen
Atmosphere 2024, 15(9), 1090; https://doi.org/10.3390/atmos15091090 - 8 Sep 2024
Viewed by 635
Abstract
Accurate forecasting of wind speeds is a crucial aspect of providing fine-scale professional meteorological services (such as wind energy generation and transportation operations etc.). This article utilizes CMA-MESO model forecast data and CARAS-SUR_1 km ground truth grid data from January, April, July, and [...] Read more.
Accurate forecasting of wind speeds is a crucial aspect of providing fine-scale professional meteorological services (such as wind energy generation and transportation operations etc.). This article utilizes CMA-MESO model forecast data and CARAS-SUR_1 km ground truth grid data from January, April, July, and October 2022, employing the random forest algorithm to establish and evaluate a downscaling correction model for near-surface 1 km resolution wind-speed grid forecast in the complex terrain area of northwestern Hebei Province. The results indicate that after downscaling correction, the spatial distribution of grid forecast wind speeds in the entire complex terrain study area becomes more refined, with spatial resolution improving from 3 km to 1 km, reflecting fine-scale terrain effects. The accuracy of the corrected wind speed forecast significantly improves compared to the original model, with forecast errors showing stability in both time and space. The mean bias decreases from 2.25 m/s to 0.02 m/s, and the root mean square error (RMSE) decreases from 3.26 m/s to 0.52 m/s. Forecast errors caused by complex terrain, forecast lead time, and seasonal factors are significantly reduced. In terms of wind speed categories, the correction significantly improves forecasts for wind speeds below 8 m/s, with RMSE decreasing from 2.02 m/s to 0.59 m/s. For wind speeds above 8 m/s, there is also a good correction effect, with RMSE decreasing from 2.20 m/s to 1.65 m/s. Selecting the analysis of the Zhangjiakou strong wind process on 26 April 2022, it was found that the downscaled corrected forecast wind speed is very close to the observed wind speed at the station and the ground truth grid points. The correction effect is particularly significant in areas affected by strong winds, such as the Bashang Plateau and valleys, which has significant reference value. Full article
(This article belongs to the Special Issue Solar Irradiance and Wind Forecasting)
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13 pages, 22146 KiB  
Article
An Automatic Jet Stream Axis Identification Method Based on Semi-Supervised Learning
by Jianhong Gan, Tao Liao, Youming Qu, Aijuan Bai, Peiyang Wei, Yuling Gan and Tongli He
Atmosphere 2024, 15(9), 1077; https://doi.org/10.3390/atmos15091077 - 6 Sep 2024
Viewed by 656
Abstract
Changes in the jet stream not only affect the persistence of climate change and the frequency of extreme weather but are also closely related to climate change phenomena such as global warming. The manual way of drawing the jet stream axes in meteorological [...] Read more.
Changes in the jet stream not only affect the persistence of climate change and the frequency of extreme weather but are also closely related to climate change phenomena such as global warming. The manual way of drawing the jet stream axes in meteorological operations suffers from low efficiency and subjectivity issues. Automatic identification algorithms based on wind field analysis have some shortcomings, such as poor generalization ability, and it is difficult to handle merging and splitting. A semi-supervised learning jet stream axis identification method is proposed combining consistency learning and self-training. First, a segmentation model is trained via semi-supervised learning. In semi-supervised learning, two neural networks with the same structure are initialized with different methods, based on which pseudo-labels are obtained. The high-confidence pseudo-labels are selected by adding perturbation into the feature layer, and the selected pseudo-labels are incorporated into the training set for further self-training. Then, the jet stream narrow regions are segmented via the trained segmentation model. Finally, the jet stream axes are obtained with the skeleton extraction method. This paper uses the semi-supervised jet stream axis identification method to learn features from unlabeled data to achieve a small amount of labeled data to effectively train the model and improve the method’s generalization ability in a small number of labeled cases. Experiments on the jet stream axis dataset show that the identification precision of the presented method on the test set exceeds about 78% for SOTA baselines, and the improved method exhibits better performance compared to the correlation network model and the semi-supervised method. Full article
(This article belongs to the Section Meteorology)
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19 pages, 10160 KiB  
Article
Performance Evaluation of TGFS Typhoon Track Forecasts over the Western North Pacific with Sensitivity Tests on Cumulus Parameterization
by Yu-Han Chen, Sheng-Hao Sha, Chang-Hung Lin, Ling-Feng Hsiao, Ching-Yuang Huang and Hung-Chi Kuo
Atmosphere 2024, 15(9), 1075; https://doi.org/10.3390/atmos15091075 - 5 Sep 2024
Viewed by 858
Abstract
This study employed the new generation Taiwan global forecast system (TGFS) to focus on its performance in forecasting the tracks of western North Pacific typhoons during 2022–2023. TGFS demonstrated better forecasting performance in typhoon track compared to central weather administration (CWA) GFS. For [...] Read more.
This study employed the new generation Taiwan global forecast system (TGFS) to focus on its performance in forecasting the tracks of western North Pacific typhoons during 2022–2023. TGFS demonstrated better forecasting performance in typhoon track compared to central weather administration (CWA) GFS. For forecasts with large track errors by TGFS at the 120th h, it was found that most of them originated during the early stages of typhoon development when the typhoons were of mild intensity. The tracks deviated predominantly towards the northeast and occasionally towards the southwest, which were speculated to be due to inadequate environmental steering guidance resulting from the failure to capture synoptic environmental features. The tracks could be corrected by replacing the original new simplified Arakawa–Schubert (NSAS) scheme with the new Tiedtke (NTDK) scheme to change the synoptic environmental field, not only for Typhoon Khanun, which occurred in the typhoon season of 2023, but also for Typhoon Bolaven, which occurred after the typhoon season, in October 2023, under atypical circulation characteristics over the western Pacific. The diagnosis of vorticity budget primarily analyzed the periods where divergence in typhoon tracks between control (CTRL) and NTDK experiments occurred. The different synoptic environmental fields in the NTDK experiment affected the wavenumber-1 vorticity distribution in the horizontal advection term, thereby enhancing the accuracy of typhoon translation velocity forecasts. This preliminary study suggests that utilizing the NTDK scheme might improve the forecasting skill of TGFS for typhoon tracks. To gain a more comprehensive understanding of the impact of NTDK on typhoon tracks, further examination for more typhoons is still in need. Full article
(This article belongs to the Special Issue Typhoon/Hurricane Dynamics and Prediction (2nd Edition))
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18 pages, 6083 KiB  
Article
First Detections of Ionospheric Plasma Density Irregularities from GOES Geostationary GPS Observations during Geomagnetic Storms
by Iurii Cherniak, Irina Zakharenkova, Scott Gleason and Douglas Hunt
Atmosphere 2024, 15(9), 1065; https://doi.org/10.3390/atmos15091065 - 3 Sep 2024
Viewed by 716
Abstract
In this study, we present the first results of detecting ionospheric irregularities using non-typical GPS observations recorded onboard the Geostationary Operational Environmental Satellites (GOES) mission operating at ~35,800 km altitude. Sitting above the GPS constellation, GOES can track GPS signals only from GPS [...] Read more.
In this study, we present the first results of detecting ionospheric irregularities using non-typical GPS observations recorded onboard the Geostationary Operational Environmental Satellites (GOES) mission operating at ~35,800 km altitude. Sitting above the GPS constellation, GOES can track GPS signals only from GPS transmitters on the opposite side of the Earth in a rather unique geometry. Although GPS receivers onboard GOES are primarily designed for navigation and were not configured for ionospheric soundings, these GPS measurements along links that traverse the Earth’s ionosphere can be used to retrieve information about ionospheric electron density. Using the radio occultation (RO) technique applied to GPS measurements from the GOES–16, we analyzed variations in the ionospheric total electron content (TEC) on the links between the GPS transmitter and geostationary GOES GPS receiver. For case-studies of major geomagnetic storms that occurred in September 2017 and August 2018, we detected and analyzed the signatures of storm-induced ionospheric irregularities in novel and promising geostationary GOES GPS observations. We demonstrated that the presence of ionospheric irregularities near the GOES GPS RO sounding field of view during geomagnetic disturbances was confirmed by ground-based GNSS observations. The use of RO observations from geostationary orbit provides new opportunities for monitoring ionospheric irregularities and ionospheric density. Full article
(This article belongs to the Special Issue Ionospheric Irregularity)
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23 pages, 8471 KiB  
Article
Impact of Polar Vortex Modes on Winter Weather Patterns in the Northern Hemisphere
by Alexis Mariaccia, Philippe Keckhut and Alain Hauchecorne
Atmosphere 2024, 15(9), 1062; https://doi.org/10.3390/atmos15091062 - 2 Sep 2024
Viewed by 857
Abstract
This study is an additional investigation of stratosphere–troposphere coupling based on the recent stratospheric winter descriptions in five distinct modes: January, February, Double, Dynamical, and Radiative. These modes, established in a previous study, categorize the main stratospheric winter typologies modulated by the timing [...] Read more.
This study is an additional investigation of stratosphere–troposphere coupling based on the recent stratospheric winter descriptions in five distinct modes: January, February, Double, Dynamical, and Radiative. These modes, established in a previous study, categorize the main stratospheric winter typologies modulated by the timing of important sudden stratospheric warmings (SSWs) and final stratospheric warmings (FSWs). The novelty of this research is to investigate the Northern Annular Mode, mean sea level pressure (MSLP) anomalies in the Ural and Aleutian regions, and the decomposition of Eliassen–Palm flux into wavenumbers 1 and 2 within each mode. The results show that the January and Double modes exhibit similar pre-warming surface signals, characterized by Ural blocking and Aleutian trough events preceding weak polar vortex events. The January mode displays a positive MSLP anomaly of +395 Pa (−191 Pa) in the Ural (Aleutian) region in December, while the Double mode shows +311 Pa (−89 Pa) in November. These modes are primarily wave-1 driven, generating tropospheric responses via negative Arctic Oscillation patterns. Conversely, the February and Dynamical modes show opposite signals, with Aleutian blocking and Ural trough events preceding strong polar vortex events. In December, the February mode exhibits MSLP anomalies of +119 Pa (Aleutian) and −180 Pa (Ural), while the Dynamical mode shows +77 Pa and −184 Pa, respectively. These modes, along with important SSWs in February and dynamical FSWs, are driven by both wave-1 and wave-2 and do not significantly impact the troposphere. The Radiative mode’s occurrence is strongly related to the Aleutian blocking presence. These findings confirm that SSW timing is influenced by specific dynamical forcing related to surface precursors and underscore its importance in subsequent tropospheric responses. This study establishes a connection between early winter tropospheric conditions and upcoming stratospheric states, potentially improving seasonal forecasts in the northern hemisphere. Full article
(This article belongs to the Section Climatology)
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15 pages, 13755 KiB  
Article
Impact of El Niño-Southern Oscillation on Dust Variability during the Spring Season over the Arabian Peninsula
by Yazeed Alsubhi and Gohar Ali
Atmosphere 2024, 15(9), 1060; https://doi.org/10.3390/atmos15091060 - 2 Sep 2024
Viewed by 816
Abstract
This study investigates the dust aerosol optical depth (DAOD) variability over the Arabian Peninsula (AP) in the spring season, a region profoundly affected by dust activity due to its desert terrain. Employing the MERRA-2 DAOD reanalysis dataset for the period 1981–2022, a significant [...] Read more.
This study investigates the dust aerosol optical depth (DAOD) variability over the Arabian Peninsula (AP) in the spring season, a region profoundly affected by dust activity due to its desert terrain. Employing the MERRA-2 DAOD reanalysis dataset for the period 1981–2022, a significant trend in DAOD is noted in the spring season compared to the other seasons. The leading Empirical Orthogonal Function (EOF) explains 67% of the total DAOD variance during the spring season, particularly over the central and northeastern parts of AP. The analysis reveals the strengthening of upper-level divergence over the western Pacific, favoring mid-tropospheric positive geopotential height anomalies over the AP, leading to warm and drier surface conditions and increased DAOD. A statistically significant negative relationship (correlation = −0.32, at 95% confidence level) is noted between DAOD over AP and the El Niño-Southern Oscillation (ENSO), suggesting that La Niña conditions may favor higher dust concentrations over the AP region and vice versa during El Niño phase. The high (low) DAOD over the region corresponds to mid-tropospheric positive (negative) geopotential height anomalies through strengthening (weakening) of the upper-level divergence (convergence) over the western Pacific during the La Niña (El Niño) phase. This study shows that ENSO could be a possible precursor to predicting dust variability on a seasonal time scale. Full article
(This article belongs to the Special Issue Recent Advances in Air-Sea Interactions, Climate Variability, and Predictability)
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20 pages, 2851 KiB  
Article
As Regular as Clockwork: Alexander von Humboldt, Robert de Lamanon and the Beginning of the Scientific Investigation of the Tidal Barometric Oscillation
by Kevin Hamilton
Atmosphere 2024, 15(9), 1052; https://doi.org/10.3390/atmos15091052 - 30 Aug 2024
Viewed by 513
Abstract
The cause of the systematic daily march of barometric pressure in the tropics, notably the late morning and late evening peaks seen almost every day at all locations, was a puzzle that persisted through the nineteenth and much of the twentieth centuries. The [...] Read more.
The cause of the systematic daily march of barometric pressure in the tropics, notably the late morning and late evening peaks seen almost every day at all locations, was a puzzle that persisted through the nineteenth and much of the twentieth centuries. The efforts to explain the physics of the prominent 12-h solar tidal variation helped inspire some of the earliest developments in theoretical atmospheric dynamics and ultimately led in the 1960’s to a satisfactory dynamical theory for the atmospheric tides. These important theoretical developments followed the observational discoveries, which date to the late 18th and early 19th centuries, of the surprising character of the barometric daily march and of its resolution into solar and lunar period cycles. These important, if simple, discoveries emerged primarily from the efforts of European scientists to systematically study the environment in remote areas of the globe. The two key figures in initially advancing the scientific community’s understanding of the character of barometric tides were the great German polymath Alexander von Humboldt (1769–1859) and the French naturalist Robert de Lamanon (1752–1787), who each made their discoveries on their most famous and colorful scientific expeditions of their respective careers. This paper examines the history of the early observations of the barometric tide. Full article
(This article belongs to the Section Meteorology)
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16 pages, 3820 KiB  
Review
Review of the Mechanisms of Liquid-Phase Transformation of Atmospheric Phenolic Compounds: Implications for Air Quality and Environmental Health
by Yuyan Yang, Xingru Li, Min Cai and Kaitao Chen
Atmosphere 2024, 15(9), 1040; https://doi.org/10.3390/atmos15091040 - 28 Aug 2024
Viewed by 642
Abstract
Phenolic compounds (PhCs) are aromatic compounds with benzene rings that have one or more hydroxyl groups. They are found or formed in the atmosphere due to various factors such as combustion processes, industrial emissions, oxidation of volatile organic compounds (VOCs), and other photochemical [...] Read more.
Phenolic compounds (PhCs) are aromatic compounds with benzene rings that have one or more hydroxyl groups. They are found or formed in the atmosphere due to various factors such as combustion processes, industrial emissions, oxidation of volatile organic compounds (VOCs), and other photochemical reactions. Due to properties such as relatively high Henry’s law constants and moderate/high water solubility, PhCs are vulnerable to reactions in atmospheric liquid phase conditions with high relative humidity, fog or cloudy conditions. PhCs can lead to the formation of secondary organic aerosols (SOAs), which can have negative effects on atmospheric conditions and human health. Changes in the optical properties of PhCs impact solar radiation absorption and scattering, potentially influencing climate. Additionally, PhCs may interact with other atmospheric constituents, potentially affecting cloud or fog formation and properties, which in turn can impact climate and precipitation patterns. Therefore, monitoring and controlling the emission of PhCs is essential. This paper discusses the transformation processes of PhCs in the atmosphere, including direct conversion of phenol, nitrate-induced and nitrite-induced reactions, hydroxylation reactions and oxidation processes involving triplet excited state organics, also providing a detailed analysis of the transformation processes. The findings lay a theoretical foundation for the future monitoring and control of atmospheric pollutants. Full article
(This article belongs to the Special Issue Research on Air Pollution and Human Exposures)
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23 pages, 9292 KiB  
Article
Potential Impacts of Future Climate Change on Super-Typhoons in the Western North Pacific: Cloud-Resolving Case Studies Using Pseudo-Global Warming Experiments
by Chung-Chieh Wang, Min-Ru Hsieh, Yi Ting Thean, Zhe-Wen Zheng, Shin-Yi Huang and Kazuhisa Tsuboki
Atmosphere 2024, 15(9), 1029; https://doi.org/10.3390/atmos15091029 - 25 Aug 2024
Viewed by 1082
Abstract
Potential impacts of projected long-term climate change toward the end of the 21st century on rainfall and peak intensity of six super-typhoons in the western North Pacific (WNP) are assessed using a cloud-resolving model (CRM) and the pseudo-global warming (PGW) method, under two [...] Read more.
Potential impacts of projected long-term climate change toward the end of the 21st century on rainfall and peak intensity of six super-typhoons in the western North Pacific (WNP) are assessed using a cloud-resolving model (CRM) and the pseudo-global warming (PGW) method, under two representative concentration pathway (RCP) emission scenarios of RCP4.5 and RCP8.5. Linear long-term trends in June–October are calculated from 38 Coupled Model Intercomparison Project phase 5 (CMIP5) models from 1981–2000 to 2081–2100, with warmings of about 3 °C in sea surface temperature, 4 °C in air temperature in the lower troposphere, and increases of 20% in moisture in RCP8.5. The changes in RCP4.5 are about half the amounts. For each typhoon, three experiments are carried out: a control run (CTL) using analysis data as initial and boundary conditions (IC/BCs), and two future runs with the trend added to the IC/BCs, one for RCP4.5 and the other for RCP8.5, respectively. Their results are compared for potential impacts of climate change. In future scenarios, all six typhoons produce more rain rather consistently, by around 10% in RCP4.5 and 20% in RCP8.5 inside 200–250 km from the center, with increased variability toward larger radii. Such increases are tested to be highly significant and can be largely explained by the increased moisture and water vapor convergence in future scenarios. However, using this method, the results on peak intensity are mixed and inconsistent, with the majority of cases becoming somewhat weaker in future runs. It is believed that in the procedure to determine the best initial time for CTL, which yielded the strongest TC, often within a few hPa in minimum central sea-level pressure to the best track data, an advantage was introduced to the CTL unintentionally. Once the long-term trends were added in future runs, the environment of the storm was altered and became not as favorable for subsequent intensification. Thus, the PGW approach may have some bias in assessing the peak intensity of such super-typhoon cases, and caution should be practiced. Full article
(This article belongs to the Special Issue Multi-Scale Climate Simulations)
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22 pages, 7765 KiB  
Article
Interpolation of Temperature in a Mountainous Region Using Heterogeneous Observation Networks
by Soorok Ryu, Joon Jin Song and GyuWon Lee
Atmosphere 2024, 15(8), 1018; https://doi.org/10.3390/atmos15081018 - 22 Aug 2024
Viewed by 923
Abstract
Accurately generating high-resolution surface grid datasets often involves merging multiple weather observation networks and addressing the challenge of network heterogeneity. This study aims to tackle the problem of accurately interpolating temperature data in regions with a complex topography. To achieve this, we introduce [...] Read more.
Accurately generating high-resolution surface grid datasets often involves merging multiple weather observation networks and addressing the challenge of network heterogeneity. This study aims to tackle the problem of accurately interpolating temperature data in regions with a complex topography. To achieve this, we introduce a deterministic interpolation method that incorporates elevation to enhance the accuracy of temperature datasets. This method is particularly valuable for areas with intricate terrains. Our robust methodology integrates a network harmonization method with radial basis function (RBF) interpolation for complex topographical regions. The method was tested on 10 min average temperature data from Jeju Island, South Korea, over 2 years that had a spatial resolution of 100 m. The results show a significant reduction of 5.5% in error rates, from an average of 0.73 °C to 0.69 °C, by incorporating all adjusted data. Integrating a parameterized nonlinear temperature profile further enhances accuracy, yielding an average reduction of 4.4% in error compared to the linear model. The spatial interpolation method, based on regression-based radial basis functions, demonstrates a 6.7% improvement over regression-based kriging for the same temperature profile. This research offers a valuable approach for precise temperature interpolation, especially in regions with a complex topography. Full article
(This article belongs to the Section Meteorology)
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18 pages, 40951 KiB  
Article
Effects of the 2024 Total Solar Eclipse on the Structure of the Planetary Boundary Layer: A Preliminary Analysis
by Robert Pasken, Richard Woodford, Jimmy Bergmann, Carter Hickel, Margaret Ideker, Riley Jackson, Jack Rotter and Benjamin Schaefer
Atmosphere 2024, 15(8), 1008; https://doi.org/10.3390/atmos15081008 - 21 Aug 2024
Viewed by 764
Abstract
A total solar eclipse provides an unparalleled opportunity to study the changes in the atmosphere’s planetary boundary layer (PBL) due to changes in radiative heating. Although previous eclipse studies have demonstrated that significant changes occur, few studies have explored the evolution of these [...] Read more.
A total solar eclipse provides an unparalleled opportunity to study the changes in the atmosphere’s planetary boundary layer (PBL) due to changes in radiative heating. Although previous eclipse studies have demonstrated that significant changes occur, few studies have explored the evolution of these changes. To better understand the changes in the lowest layers of the PBL during an eclipse, a multi-sensor sampling approach was taken. Radiosonde launches were used to explore the depth of the column, while Unmanned Aerial Vehicles (UAVs) were used to document with high-resolution the brief changes in the vertical structure of the PBL caused by the eclipse. These changes highlighted differences from previous studies that relied solely on radiosonde and/or mesonet data alone. Higher-resolution sampling of the lower PBL showed a delay in the local vertical mixing as well as changes in the PBL height from pre- to post-eclipse. Slow responses were noted at the top of the PBL while very rapid changes to the PBL profile were captured in the near-surface layer. These changes highlighted differences from previous studies that relied solely on radiosonde and/or mesonet data alone. A preliminary analysis of the collected data highlighted a slow response to the eclipse near the top of the planetary boundary layer (radiosonde data) with very rapid changes noted in the near surface layer (UAV data). Preliminary results show that PBL heights remained nearly constant until well after third contact when a 35 hPa lowering of the PBL heights was observed and were limited to the lowest 25 hPa. The UAV soundings demonstrated the development of a strong inversion where the air below 990 hPa rapidly cooled with a nearly 1 °C drop in temperature observed. These observed changes raise interesting questions about how the lower and upper parts of the planetary boundary layer interact. Full article
(This article belongs to the Section Atmospheric Techniques, Instruments, and Modeling)
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14 pages, 1481 KiB  
Review
Recent Advances in SCR Systems of Heavy-Duty Diesel Vehicles—Low-Temperature NOx Reduction Technology and Combination of SCR with Remote OBD
by Zhengguo Chen, Qingyang Liu, Haoye Liu and Tianyou Wang
Atmosphere 2024, 15(8), 997; https://doi.org/10.3390/atmos15080997 - 20 Aug 2024
Viewed by 1851
Abstract
Heavy-duty diesel vehicles are a significant source of nitrogen oxides (NOx) in the atmosphere. The Selective Catalytic Reduction (SCR) system is a primary aftertreatment device for reducing NOx emissions from heavy-duty diesel vehicles. With increasingly stringent NOx emission regulations for heavy-duty vehicles in [...] Read more.
Heavy-duty diesel vehicles are a significant source of nitrogen oxides (NOx) in the atmosphere. The Selective Catalytic Reduction (SCR) system is a primary aftertreatment device for reducing NOx emissions from heavy-duty diesel vehicles. With increasingly stringent NOx emission regulations for heavy-duty vehicles in major countries, there is a growing focus on reducing NOx emissions under low exhaust temperature conditions, as well as monitoring the conversion efficiency of the SCR system over its entire lifecycle. By reviewing relevant literature mainly from the past five years, this paper reviews the development trends and related research results of SCR technology, focusing on two main aspects: low-temperature NOx reduction technology and the combination of SCR systems with remote On-Board Diagnostics (OBD). Regarding low-temperature NOx reduction technology, the results of the review indicate that the combination of multiple catalytic shows potential for achieving high conversion efficiency across a wide temperature range; advanced SCR system arrangement can accelerate the increase in exhaust temperature within the SCR system; solid ammonium and gaseous reductants can effectively address the issue of urea not being able to be injected under low-temperature exhaust conditions. As for the combination of SCR systems with remote OBD, remote OBD can accurately assess NOx emissions from heavy-duty vehicles, but it needs algorithms to correct data and match the emission testing process required by regulations. Remote OBD systems are crucial for detecting SCR tampering, but algorithms must be developed to balance accuracy with computational efficiency. This review provides updated information on the current research status and development directions in SCR technologies, offering valuable insights for future research into advanced SCR systems. Full article
(This article belongs to the Special Issue Recent Advances in Mobile Source Emissions (2nd Edition))
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10 pages, 3070 KiB  
Article
A Generalised Additive Model and Deep Learning Method for Cross-Validating the North Atlantic Oscillation Index
by Md Wahiduzzaman and Alea Yeasmin
Atmosphere 2024, 15(8), 987; https://doi.org/10.3390/atmos15080987 - 17 Aug 2024
Viewed by 645
Abstract
This study introduces an innovative analytical methodology for examining the interconnections among the atmosphere, ocean, and society. The primary area of interest pertains to the North Atlantic Oscillation (NAO), a notable phenomenon characterised by daily to decadal fluctuations in atmospheric conditions over the [...] Read more.
This study introduces an innovative analytical methodology for examining the interconnections among the atmosphere, ocean, and society. The primary area of interest pertains to the North Atlantic Oscillation (NAO), a notable phenomenon characterised by daily to decadal fluctuations in atmospheric conditions over the Northern Hemisphere. The NAO has a prominent impact on winter weather patterns in North America, Europe, and to some extent, Asia. This impact has significant ramifications for civilization, as well as for marine, freshwater, and terrestrial ecosystems, and food chains. Accurate predictions of the surface NAO hold significant importance for society in terms of energy consumption planning and adaptation to severe winter conditions, such as winter wind and snowstorms, which can result in property damage and disruptions to transportation networks. Moreover, it is crucial to improve climate forecasts in order to bolster the resilience of food systems. This would enable producers to quickly respond to expected changes and make the required modifications, such as adjusting their food output or expanding their product range, in order to reduce potential hazards. The forecast centres prioritise and actively research the predictability and variability of the NAO. Nevertheless, it is increasingly evident that conventional analytical methods and prediction models that rely solely on scientific methodologies are inadequate in comprehensively addressing the transdisciplinary dimension of NAO variability. This includes a comprehensive view of research, forecasting, and social ramifications. This study introduces a new framework that combines sophisticated Big Data analytic techniques and forecasting tools using a generalised additive model to investigate the fluctuations of the NAO and the interplay between the ocean and atmosphere. Additionally, it explores innovative approaches to analyze the socio-economic response associated with these phenomena using text mining tools, specifically modern deep learning techniques. The analysis is conducted on an extensive corpora of free text information sourced from media outlets, public companies, government reports, and newspapers. Overall, the result shows that the NAO index has been reproduced well by the Deep-NAO model with a correlation coefficient of 0.74. Full article
(This article belongs to the Special Issue Satellite Observations of Ocean–Atmosphere Interaction)
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29 pages, 23715 KiB  
Article
Forecasting In-Flight Icing over Greece: Insights from a Low-Pressure System Case Study
by Petroula Louka, Ioannis Samos and Flora Gofa
Atmosphere 2024, 15(8), 990; https://doi.org/10.3390/atmos15080990 - 17 Aug 2024
Viewed by 1151
Abstract
Forecasting in-flight icing conditions is crucial for aviation safety, particularly in regions with variable and complex meteorological configurations, such as Greece. Icing accretion onto the aircraft’s surfaces is influenced by the presence of supercooled water in subfreezing environments. This paper outlines a methodology [...] Read more.
Forecasting in-flight icing conditions is crucial for aviation safety, particularly in regions with variable and complex meteorological configurations, such as Greece. Icing accretion onto the aircraft’s surfaces is influenced by the presence of supercooled water in subfreezing environments. This paper outlines a methodology of forecasting icing conditions, with the development of the Icing Potential Algorithm that takes into consideration the meteorological scenarios related to icing accretion, using state-of-the-art Numerical Weather Prediction model results, and forming a fuzzy logic tree based on different membership functions, applied for the first time over Greece. The synoptic situation of an organized low-pressure system passage, with occlusion, cold and warm fronts, over Greece that creates dynamically significant conditions for icing formation was investigated. The sensitivity of the algorithm was revealed upon the precipitation, cloud type and vertical velocity effects. It was shown that the greatest icing intensity is associated with single-layer ice and multi-layer clouds that are comprised of both ice and supercooled water, while convectivity and storm presence lead to also enhancing the icing formation. A qualitative evaluation of the results with satellite, radar and METAR observations was performed, indicating the general agreement of the method mainly with the ground-based observations. Full article
(This article belongs to the Special Issue Numerical Weather Prediction Models and Ensemble Prediction Systems)
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17 pages, 5526 KiB  
Article
Generating Daily High-Resolution Regional XCO2 by Deep Neural Network and Multi-Source Data
by Wenjie Tian, Lili Zhang, Tao Yu, Dong Yao, Wenhao Zhang and Chunmei Wang
Atmosphere 2024, 15(8), 985; https://doi.org/10.3390/atmos15080985 - 16 Aug 2024
Viewed by 578
Abstract
CO2 is one of the primary greenhouse gases impacting global climate change, making it crucial to understand the spatiotemporal variations of CO2. Currently, commonly used satellites serve as the primary means of CO2 observation, but they often suffer from [...] Read more.
CO2 is one of the primary greenhouse gases impacting global climate change, making it crucial to understand the spatiotemporal variations of CO2. Currently, commonly used satellites serve as the primary means of CO2 observation, but they often suffer from striping issues and fail to achieve complete coverage. This paper proposes a method for constructing a comprehensive high-spatiotemporal-resolution XCO2 dataset based on multiple auxiliary data sources and satellite observations, utilizing multiple simple deep neural network (DNN) models. Global validation results against ground-based TCCON data demonstrate the excellent accuracy of the constructed XCO2 dataset (R is 0.94, RMSE is 0.98 ppm). Using this method, we analyze the spatiotemporal variations of CO2 in China and its surroundings (region: 0°–60° N, 70°–140° E) from 2019 to 2020. The gapless and fine-scale CO2 generation method enhances people’s understanding of CO2 spatiotemporal variations, supporting carbon-related research. Full article
(This article belongs to the Special Issue Satellite Remote Sensing Applied in Atmosphere (2nd Edition))
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12 pages, 2193 KiB  
Case Report
Indoor Concentration Distributions of Ammonia and Sulfur-Based Odorous Substances According to Types of Laying Hen Houses in South Korea
by Ki-Youn Kim and Jung-Kon Kim
Atmosphere 2024, 15(8), 980; https://doi.org/10.3390/atmos15080980 - 15 Aug 2024
Viewed by 463
Abstract
In South Korea, environmental complaints related to livestock odors continue to increase, and various efforts are underway to overcome them. An objective of this study is to monitor indoor concentrations of ammonia and sulfur-based odorous substances emitted from laying hen houses in South [...] Read more.
In South Korea, environmental complaints related to livestock odors continue to increase, and various efforts are underway to overcome them. An objective of this study is to monitor indoor concentrations of ammonia and sulfur-based odorous substances emitted from laying hen houses in South Korea through on-site visits for one year to understand their temporal emission patterns. The highest concentration was found in ammonia (NH3), at 6.92 ppmv, followed by hydrogen sulfide (H2S), at 8.98 ppbv. The concentrations of methyl mercaptan (CH3SH), dimethyl sulfide (DMS), and dimethyldisulfide (DMDS) ranged from sub ppbv to 10 ppbv. In general, there was no consistent concentration distribution of ammonia and sulfur-based odorous substances in laying hen houses between those with forced ventilation and natural ventilation. Regarding the seasonal distribution of odorous compounds, their concentrations in winter season (December to February) when the ventilation rate in laying hen houses decreased were generally higher than those in the summer season (June to August) when the ventilation rate in poultry buildings was relatively high, which is applied to properly maintain the thermal environment in laying hen houses. The limitation of this study is that unexpected conditions such as clearance of laying hen houses, chicken shipments, and disorders of exhaust fans were not controlled for intentionally due to on-site investigations. Full article
(This article belongs to the Section Air Pollution Control)
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13 pages, 2115 KiB  
Article
Influence of Time–Activity Patterns on Indoor Air Quality in Italian Restaurant Kitchens
by Marta Keller, Davide Campagnolo, Francesca Borghi, Alessio Carminati, Giacomo Fanti, Sabrina Rovelli, Carolina Zellino, Rocco Loris Del Vecchio, Giovanni De Vito, Andrea Spinazzé, Viktor Gábor Mihucz, Carlo Dossi, Mariella Carrieri, Andrea Cattaneo and Domenico Maria Cavallo
Atmosphere 2024, 15(8), 976; https://doi.org/10.3390/atmos15080976 - 15 Aug 2024
Viewed by 832
Abstract
This study aims to delve deeper into the relationship between the professional activities carried out in restaurant kitchens and some key air pollutants. The ultrafine particles (UFPs), nitrogen dioxide (NO2), ozone (O3), Total Volatile Organic Compounds (TVOCs) and formaldehyde [...] Read more.
This study aims to delve deeper into the relationship between the professional activities carried out in restaurant kitchens and some key air pollutants. The ultrafine particles (UFPs), nitrogen dioxide (NO2), ozone (O3), Total Volatile Organic Compounds (TVOCs) and formaldehyde (HCHO) indoor air concentrations were determined using real-time monitors. Simultaneously, the kitchen environment was characterized using video recordings with the aim to retrieve information pertaining to cooking, cookware washing and surface cleaning activities. Statistical analysis was carried out separately for the winter and summer campaigns. The obtained results confirmed that the professional activities carried out in restaurant kitchens had a significant impact on the concentrations of all the selected pollutants. Specifically, this study revealed the following key results: (i) indoor UFPs and NO2 concentrations were significantly higher during cooking than during washing activities (e.g., about +60% frying vs. handwashing and dishwasher running), mainly in the winter; (ii) washing activity had a statistically significant impact on the TVOC (+39% on average) and HCHO (+67% on average) concentrations compared to other activities; (iii) some specific sources of short-term pollutant emissions have been identified, such as the different types of cooking and opening the dishwasher; and (iv) in some restaurants, a clear time-dependent relationship between O3 and UFP, TVOC and HCHO has been observed, underlining the occurrence of ozonolysis reactions. Full article
(This article belongs to the Special Issue Exposure Assessment of Air Pollution (2nd Edition))
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26 pages, 6003 KiB  
Article
Seasonal Contributions and Influencing Factors of Urban Carbon Emission Intensity: A Case Study of Tianjin, China
by Tianchun Xiang, Jiang Bian, Yumeng Li, Yiming Gu, Yang Wang, Yahui Zhang and Junfeng Wang
Atmosphere 2024, 15(8), 947; https://doi.org/10.3390/atmos15080947 - 8 Aug 2024
Viewed by 768
Abstract
The escalating concern over global warming has garnered significant international attention, with carbon emission intensity emerging as a crucial barrier to sustainable economic development across various regions. While previous studies have largely focused on annual scales, this study introduces a novel examination of [...] Read more.
The escalating concern over global warming has garnered significant international attention, with carbon emission intensity emerging as a crucial barrier to sustainable economic development across various regions. While previous studies have largely focused on annual scales, this study introduces a novel examination of Tianjin’s quarterly carbon emission intensity and its influencing factors from 2012 to 2022 using quarterly data and the Logarithmic Mean Divisia Index (LMDI) model. The analysis considers the carbon emission effects of thermal power generation, the power supply structure, power intensity effects, and economic activity intensity. The results indicate a general decline in Tianjin’s carbon emission intensity from 2012 to 2020, followed by an increase in 2021 and 2022. This trend, exhibiting significant seasonal fluctuations, revealed the highest carbon emission intensity in the first quarter (an average of 1.4093) and the lowest in the second quarter (an average of 1.0019). Economic activity intensity emerged as the predominant factor influencing carbon emission intensity changes, particularly notable in the second quarter (an average of −0.0374). Thermal power generation and electricity intensity effects were significant in specific seasons, while the power supply structure’s impact remained relatively minor yet stable. These findings provide essential insights for formulating targeted carbon reduction strategies, underscoring the need to optimize energy structures, enhance energy efficiency, and account for the seasonal impacts of economic activity patterns on carbon emissions. Full article
(This article belongs to the Special Issue Urban Carbon Emissions)
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16 pages, 1432 KiB  
Article
On the Relation between Wind Speed and Maximum or Mean Water Wave Height
by Sarah Balkissoon, Y. Charles Li, Anthony R. Lupo, Samuel Walsh and Lukas McGuire
Atmosphere 2024, 15(8), 948; https://doi.org/10.3390/atmos15080948 - 8 Aug 2024
Viewed by 580
Abstract
Dimensional analysis shows that the relation between wind speed and maximum or mean water wave height takes the form H=cU02g, where H is the maximum or mean water wave height caused by wind of speed [...] Read more.
Dimensional analysis shows that the relation between wind speed and maximum or mean water wave height takes the form H=cU02g, where H is the maximum or mean water wave height caused by wind of speed U0, g is the gravitational acceleration, and c is a dimensionless constant. This relation is important in predicting the maximum or mean water wave height caused by a tropical cyclone. Firstly, the mathematical and theoretical justification for determining c is presented. Verification is conducted using four tropical cyclones as case studies for determining c using significant wave heights rather than the overall maximum and mean. The observed values of c are analyzed statistically. On the days when the fixed buoy captured the highest wind speeds, the frequency distributions of the data for c are close to a bell shape with very small standard deviations in comparison with the mean values; thus, the mean values provide good predictions for c. In view of the fact that tropical cyclone waves are turbulent and the background waves caused by many other factors such as lunar tidal effect cannot be ignored, the obtained results for c are quite satisfactory. This method provides a direct approach in the prediction of the wave height or the wind speeds given the c value and can serve an interpolation methodology to increase the temporal resolution of the data. Full article
(This article belongs to the Section Meteorology)
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14 pages, 4076 KiB  
Article
Observed Impacts of Ground-Mounted Photovoltaic Systems on the Microclimate and Soil in an Arid Area of Gansu, China
by Jia Zhang, Zaixin Li, Junyu Tao, Yadong Ge, Yuzhen Zhong, Yibo Wang and Beibei Yan
Atmosphere 2024, 15(8), 936; https://doi.org/10.3390/atmos15080936 - 5 Aug 2024
Cited by 1 | Viewed by 731
Abstract
Ground-mounted photovoltaic (GMPV) systems are a crucial component of photovoltaic (PV) applications, and their environmental impacts during large-scale development require thorough attention. This study conducted continuous observations at a GMPV plant in an arid region, employing a three-site comparative monitoring system to assess [...] Read more.
Ground-mounted photovoltaic (GMPV) systems are a crucial component of photovoltaic (PV) applications, and their environmental impacts during large-scale development require thorough attention. This study conducted continuous observations at a GMPV plant in an arid region, employing a three-site comparative monitoring system to assess the environmental impact of both shaded and non-shaded areas within GMPV systems. The parameters measured included atmospheric temperature (AT), relative humidity (RH), soil temperature (ST), soil water content (SWC), and wind speed. The results revealed significant diurnal and seasonal variations in AT, with daytime warming and nighttime cooling ranging from 0.1 to 0.7 °C, with particularly large variations observed during high-temperature seasons. Shaded areas under the PV panels exhibited increased RH at night and decreased RH during the day, along with a cooling effect on ST, with a maximum reduction of 7 °C. SWC was higher in shaded areas during dry seasons but exhibited complex redistribution patterns during rainy seasons. Wind speed and direction were notably altered, demonstrating a corridor effect. These findings contrast with previous studies that only focused on the environmental assessment of non-shaded areas within PV systems and external areas using two-site monitoring. This study highlights the critical role of shaded areas in understanding the local environmental impacts of PV systems. This comprehensive approach offers deeper insights into how PV systems influence local meteorological and environmental conditions, suggesting that optimized design and placement of PV systems can enhance their ecological benefits and mitigate adverse environmental impacts in arid regions. Full article
(This article belongs to the Special Issue Science and Technology of Indoor and Outdoor Environment)
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28 pages, 6734 KiB  
Article
Carbon Reduction Pathways for Chinese Provinces: Considering Carbon Intensity Convergence, Regional Development Plans, and Shared Socioeconomic Pathways
by Fanglei Zhong, Yanjie Yin, Jingwen Tian, Daiwei Jiang and Yijun Mao
Atmosphere 2024, 15(8), 918; https://doi.org/10.3390/atmos15080918 - 31 Jul 2024
Viewed by 668
Abstract
The achievement of dual carbon goals varies significantly across Chinese provinces due to the differences in resource endowments and socioeconomic development levels. These variations impose distinct pressures for transitioning along different socioeconomic development paths. Exploration of orderly carbon reduction paths for each province [...] Read more.
The achievement of dual carbon goals varies significantly across Chinese provinces due to the differences in resource endowments and socioeconomic development levels. These variations impose distinct pressures for transitioning along different socioeconomic development paths. Exploration of orderly carbon reduction paths for each province is, thus, crucial, but current predictions have not adequately integrated provincial development plans and carbon emission convergence trends. This study combines the Intergovernmental Panel on Climate Change (IPCC’s) shared socioeconomic pathways (SSPs) with a dual-layer target-setting approach based on trends in carbon emissions and each province’s five-year plans. The scalable stochastic impacts by regression on population, affluence, and technology (STIRPAT) model and ridge regression method were employed to identify the factors influencing carbon emissions. Carbon peak values and timing were then predicted for provinces under different scenarios. The results indicate that total carbon emissions are primarily influenced by provincial economic level and population, with spatial and temporal variations in the driving factors. Carbon emissions are ranked from low to high in the following order: SSP1, SSP2, and SSP5. Provinces were categorized into four tiers based on their peak times: early, on-time, delayed, and significantly delayed peaking. Under SSP1, 24 provinces would achieve carbon peaking as scheduled. Under SSP2, only 17 provinces would achieve carbon peaking on time. Among the first-tier provinces, Beijing and Shanghai would achieve peak carbon five to eight years ahead of schedule; the second-tier provinces of Henan, Fujian, Guangdong, and Inner Mongolia would achieve peak carbon by 2030; the third tier would achieve carbon peak before 2035; and the fourth tier would gradually reach peak carbon before 2050. Policy implications for differentiated carbon peak paths are proposed for different regions based on these findings. Full article
(This article belongs to the Special Issue Carbon Emission and Carbon Neutrality in China)
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23 pages, 4832 KiB  
Article
Influence of Short-Term Variations in Solar Activity on Total Electron Content
by Plamen Mukhtarov and Rumiana Bojilova
Atmosphere 2024, 15(8), 913; https://doi.org/10.3390/atmos15080913 - 30 Jul 2024
Viewed by 655
Abstract
In the present work, the variations in Total Electron Content (TEC) induced by changes in the ionizing radiation of the Sun, which are related to the rotation period (about 27 days), were investigated. This study was based on a 30-year period. The relative [...] Read more.
In the present work, the variations in Total Electron Content (TEC) induced by changes in the ionizing radiation of the Sun, which are related to the rotation period (about 27 days), were investigated. This study was based on a 30-year period. The relative deviations in the TEC and F10.7 values were used in the data analysis. The use of this modification aimed to eliminate the stationary diurnal, seasonal, and solar course of the TEC over the course of the long-term variations in solar activity, preserving the variations within a time scale of 27 days and less. As a result, the values of the linear regression coefficient between the relative deviations in the two considered quantities from the median (quiet conditions) for one rotation period were obtained. Depending on the general level of solar activity, the season, and the latitude, this coefficient varied between 40% and 60%. The analysis showed that the minimum values were observed during high solar activity. The latitudinal distribution demonstrated an increase in the area of the Equatorial Ionization Anomaly (EIA) under the influence of the so-called “fountain effect”. As a result, there was a seasonal variation and an increase in the winter months at mid and high latitudes and a decrease in the months of the minimum zenith angle of the Sun at low latitudes. A well-pronounced asymmetry in the equinox months was also obtained. The obtained results are the novelty of this study and can be used to improve empirical models for short-term TEC forecasting. Full article
(This article belongs to the Section Upper Atmosphere)
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20 pages, 8429 KiB  
Article
Optimization of High-Temperature CO2 Capture by Lithium Orthosilicate-Based Sorbents Using Response Surface Methodology
by Eleonora Stefanelli, Flavio Francalanci, Sandra Vitolo and Monica Puccini
Atmosphere 2024, 15(8), 908; https://doi.org/10.3390/atmos15080908 - 30 Jul 2024
Cited by 1 | Viewed by 799
Abstract
The major challenge in the current context of the rising world energy demand is to limit the global temperature increase for mitigating climate change. This goal requires a large reduction of CO2 emissions, mainly produced by power generation and industrial processes using [...] Read more.
The major challenge in the current context of the rising world energy demand is to limit the global temperature increase for mitigating climate change. This goal requires a large reduction of CO2 emissions, mainly produced by power generation and industrial processes using fossil fuels. In this study, a novel methodology for K2CO3-doped Li4SiO4 sorbents production for CO2 capture at high temperatures was adopted based on the Design of Experiments (DoE). This innovative approach systematically tested different synthesis (temperature and K2CO3 content) and adsorption conditions (sorption temperature and CO2 concentration), allowing for the assessment of individual and interactive effects of process parameters. The Response Surface Methodology (RSM) was employed to obtain non-linear predictive models of CO2 uptake and Li4SiO4 conversion. The results of RSM analysis evidenced a maximum adsorption capacity of 196.4 mg/g for a sorbent produced at 600 °C and with 36.9 wt% of K2CO3, tested at 500 °C and 4 vol% of CO2. Whereas at 50 vol% of CO2, the best uptake of 295.6 mg/g was obtained with a sorbent synthesized at 600 °C, containing less K2CO3 (17.1 wt%) and tested at a higher temperature (662 °C). These findings demonstrate that K2CO3-doped Li4SiO4 sorbents can be tailored to maximize CO2 capture under various operating conditions, making them suitable for use in industrial processes. Full article
(This article belongs to the Special Issue Advances in CO2 Capture and Absorption)
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14 pages, 3708 KiB  
Article
Properties of Medium-Scale Traveling Ionospheric Disturbances Observed over Mexico during Quiet Solar Activity
by Esmeralda Romero-Hernandez, Federico Salinas-Samaniego, Olusegun F. Jonah, Ernesto Aguilar-Rodriguez, Mario Rodriguez-Martinez, Giorgio Arlan da Silva Picanço, Clezio M. Denardini, Carlos Alberto Guerrero-Peña, Rogelio Aguirre-Gutierrez, Flor Araceli Garcia-Castillo, Sandra Ayala, Eduardo Perez-Tijerina, Maria A. Sergeeva and Juan Americo Gonzalez-Esparza
Atmosphere 2024, 15(8), 894; https://doi.org/10.3390/atmos15080894 - 26 Jul 2024
Viewed by 587
Abstract
We present a statistical study of some physical properties of medium-scale traveling ionospheric disturbances (MSTIDs) registered over the Mexican territory during 2018 and 2019 (solar minimum). The analysis is based on total electron content (TEC) approximations using data from [...] Read more.
We present a statistical study of some physical properties of medium-scale traveling ionospheric disturbances (MSTIDs) registered over the Mexican territory during 2018 and 2019 (solar minimum). The analysis is based on total electron content (TEC) approximations using data from the ground-based Global Navigation Satellite System (GNSS) receivers at different locations, divided into three regions according to geographic longitudes: west, center, and east. The MSTIDs were classified into day and night events, and only geomagnetically quiet days were considered to reduce the solar influence. We explored fundamental aspects of the MSTIDs, such as differences between day and night events, occurrence patterns, and geographical differences. Our results show some similarities with the occurrence periods of gravity waves, exhibiting high activity during summer and winter. For this period, however, most events occurred between 20:00 and 04:00 AM UT. The most energetic events, i.e., large amplitudes and power, occurred around the sunset terminator. This suggests that the density gradient generated when the sunlight falls benefits MSTID formation. Full article
(This article belongs to the Special Issue Recent Advances in Ionosphere Observation and Investigation (2nd Edition))
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18 pages, 4078 KiB  
Article
Variations in Air Pollutant Concentrations on Dry and Wet Days with Varying Precipitation Intensity
by Veli Yavuz
Atmosphere 2024, 15(8), 896; https://doi.org/10.3390/atmos15080896 - 26 Jul 2024
Viewed by 690
Abstract
In this study, concentrations of three different air pollutants (PM10, SO2, and NO2) were obtained from four air quality monitoring stations (AQMSs) over an 11-year period from 2013 to 2023. Meteorological variables (temperature, dew point temperature, wind [...] Read more.
In this study, concentrations of three different air pollutants (PM10, SO2, and NO2) were obtained from four air quality monitoring stations (AQMSs) over an 11-year period from 2013 to 2023. Meteorological variables (temperature, dew point temperature, wind speed, sea level pressure, and precipitation) were then obtained from the nearest European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis v5 (ERA5) grid point to each station, and their relationships were analyzed. Homogeneity and normality tests were conducted for air pollutant concentrations and meteorological variables, followed by data preprocessing analyses using non-parametric tests. The ultimate aim of this study is to determine the effects of the presence and intensity of precipitation on pollutant concentrations. Analyses based on four different precipitation intensity categories (light, moderate, heavy, and severe) indicated that increasing precipitation intensity is associated with decreasing pollutant concentrations. Specifically, higher precipitation intensities were associated with a reduction in pollutant levels, with reductions ranging from 15% to 35% compared to dry conditions. This effect was particularly pronounced during the winter season, when PM10 concentrations decreased by up to 45% on wet days compared to dry days. This finding highlighted the importance of not only precipitation intensity but also the type of hydrometeor for air pollution. The significant decrease observed during winter is thought to be due to snowfall, which is believed to have a greater removal effect on air pollution compared to rain. Full article
(This article belongs to the Section Meteorology)
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28 pages, 6583 KiB  
Article
Artificial Intelligence-Based Detection of Light Points: An Aid for Night-Time Visibility Observations
by Zuzana Gáborčíková, Juraj Bartok, Irina Malkin Ondík, Wanda Benešová, Lukáš Ivica, Silvia Hnilicová and Ladislav Gaál
Atmosphere 2024, 15(8), 890; https://doi.org/10.3390/atmos15080890 - 25 Jul 2024
Viewed by 828
Abstract
Visibility is one of the key meteorological parameters with special importance in aviation meteorology and the transportation industry. Nevertheless, it is not a straightforward task to automatize visibility observations, since the assistance of trained human observers is still inevitable. The current paper attempts [...] Read more.
Visibility is one of the key meteorological parameters with special importance in aviation meteorology and the transportation industry. Nevertheless, it is not a straightforward task to automatize visibility observations, since the assistance of trained human observers is still inevitable. The current paper attempts to make the first step in the process of automated visibility observations: it examines, by the approaches of artificial intelligence (AI), whether light points in the target area can or cannot be automatically detected for the purposes of night-time visibility observations. From a technical point of view, our approach mimics human visibility observation of the whole circular horizon by the usage of camera imagery. We evaluated the detectability of light points in the camera images (1) based on an AI approach (convolutional neural network, CNN) and (2) based on a traditional approach using simple binary thresholding (BT). The models based on trained CNN achieved remarkably better results in terms of higher values of statistical metrics, and less susceptibility to errors than the BT-based method. Compared to BT, the CNN classification method indicated greater stability since the accuracy of these models grew with increasing pixel size around the key points. This fundamental difference between the approaches was also confirmed through the Mann–Whitney U test. Thus, the presented AI-based determination of key points’ detectability in the night with decent accuracy has great potential in the objectivization of everyday routines of professional meteorology. Full article
(This article belongs to the Special Issue Problems of Meteorological Measurements and Studies (2nd Edition))
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18 pages, 30190 KiB  
Article
Climate Change and Viticulture in Italy: Historical Trends and Future Scenarios
by Vittorio Alba, Alessandra Russi, Angelo Raffaele Caputo and Giovanni Gentilesco
Atmosphere 2024, 15(8), 885; https://doi.org/10.3390/atmos15080885 - 25 Jul 2024
Cited by 1 | Viewed by 982
Abstract
(1) Background: The aim of this work was to characterize climatic evolution and change based on multicriteria classification through the dynamics of bioclimatic indices in viticulture across Italy and its regional administrative boundaries, focusing on latitudes and elevations. (2) Methods: This study analyzes [...] Read more.
(1) Background: The aim of this work was to characterize climatic evolution and change based on multicriteria classification through the dynamics of bioclimatic indices in viticulture across Italy and its regional administrative boundaries, focusing on latitudes and elevations. (2) Methods: This study analyzes climate change influences on Italian viticulture with reference to historical information (1991–2021) and future scenarios (until 2080) primarily based on the SSP2-4.5 and SSP5-8.5 scenarios, taking into account 13 GCMs. (3) Results: The bioclimatic indices have all shown a significant trend in the historical period, with an increase in temperature and a decrease in precipitation, reflecting their effects on the entire Italian territory with respect to the HI, up to 44° N for the CI, and up to 46° N for the DI, regardless of altitude. The future scenarios highlighted a shift towards the warmer classes of the two temperature-based indices (HI and CI) for both SSPs, especially for altitudes up to 900 m a.s.l. The DI-based classification based on the DI remained relatively stable in Italy over time, although DI values will become increasingly negative in the near future. (4) Conclusions: The climate in Italy is warming, especially in the south and in the coastal regions. By 2080, more areas will be “very hot” with “warm nights”. Drought will also increase and have a negative impact on viticulture. These findings spotlight the need for adaptive strategies in viticulture to hold satisfactory productivity under changing climatic conditions. Full article
(This article belongs to the Special Issue Climate Change Impacts and Adaptation Strategies in Agriculture)
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20 pages, 4402 KiB  
Article
Testing Strategies for Planting Design in Urban Squares to Improve Human Comfort throughout the Seasons
by Priscila Weruska Stark da Silva, Denise Helena Silva Duarte, Mohammad Asrafur Rahman, Thomas Rötzer and Stephan Pauleit
Atmosphere 2024, 15(8), 870; https://doi.org/10.3390/atmos15080870 - 23 Jul 2024
Cited by 2 | Viewed by 2062
Abstract
Green urban squares are essential in densely built neighborhoods and enhance their quality of life. Investment in the greening of urban areas will have a beneficial impact, particularly regarding human thermal comfort. Smaller than parks, squares can be easily spread over the cities [...] Read more.
Green urban squares are essential in densely built neighborhoods and enhance their quality of life. Investment in the greening of urban areas will have a beneficial impact, particularly regarding human thermal comfort. Smaller than parks, squares can be easily spread over the cities and should be part of any neighborhood. While the cooling effect of green squares during hot summer days is increasingly well established, microclimatic assessments during all seasons are still missing. This study aimed to determine whether it is possible to identify an optimal greenery design that maximizes human thermal comfort, as indexed by physiological equivalent temperature (PET), in temperate climates across all seasons. This study employed a “research by design” methodology, utilizing the micrometeorological simulation model ENVI-met to analyze the impact of greenery on PET improvement across different seasons. The objective was to identify the most effective combination of greenery for PET improvement. To achieve these objectives, two urban squares in Munich, Germany were selected. This selection was based on the assumption that typical greening practices, exemplified by the presence of trees, shrubs, and grass, would significantly impact urban squares and their microclimatic effects on human thermal comfort. The small square with a grass surface underneath trees, Alpenplatz, is highly influenced by the surrounding buildings, affecting the sky view factor (SVF), a crucial aspect of the urban environment. Marstallplatz, an open, large square that is not highly affected by urban morphology, was analyzed through simulation scenarios combining grass, shrubs, and trees. The results demonstrate that hot summer days are of primary concern for climate-sensitive urban square design in order to avoid health risks and thus need to be prioritized without compromising comfort for cold days. To attend to both needs, increasing the number of deciduous trees for shading during the day and the amount of grass to enhance air cooling at night are particularly effective. Nevertheless, microclimate design for the spring and autumn periods must also be considered, with the provision of adaptable opportunities for sheltered and sun-exposed spaces. Full article
(This article belongs to the Special Issue Vegetation and Climate Relationships (3rd Edition))
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15 pages, 10073 KiB  
Article
Deciphering East Atlantic Low-Pressure System Formations: Exploring the Nexus of Tropical Jet Streams and Active Monsoon Phases
by Vinay Kumar, Dipak K. Sahu, Katelyn Simonsen and Sabrina Gonzalez
Atmosphere 2024, 15(7), 862; https://doi.org/10.3390/atmos15070862 - 21 Jul 2024
Viewed by 967
Abstract
The formation of low-pressure systems (LPSs) over the eastern Atlantic Ocean, near the coast of West Africa, is an exceptional meteorological/climatological feature that can lead to the development of hurricanes. The upper level diffluence induced by the Tropical Easterly Jet (TEJ) plays a [...] Read more.
The formation of low-pressure systems (LPSs) over the eastern Atlantic Ocean, near the coast of West Africa, is an exceptional meteorological/climatological feature that can lead to the development of hurricanes. The upper level diffluence induced by the Tropical Easterly Jet (TEJ) plays a crucial role in the formation of LPSs over the eastern Atlantic Ocean, off the coast of West Africa. However, the exact influence of the enhanced TEJ and diffluence in relation to cyclogenesis remains unclear. An active precipitation period over the Indian subcontinent and Africa induces an intensification of the TEJ, African Easterly Jet, and the bifurcation of diffluence off the coast of Africa. Over the past five years (2019–2023), a delayed correlation has been observed between the formation of LPSs over the eastern Atlantic Ocean (7.5° N–20° N, 15° W–41° W), the TEJ over the Indian subcontinent (approximately 2 to 3 days), and the AEJ over Africa (approximately 1 day). This correlation is further linked to the bifurcation of diffluence at the 200 mb level. Full article
(This article belongs to the Section Meteorology)
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21 pages, 5512 KiB  
Article
Assessing Multi-Scale Atmospheric Circulation Patterns for Improvements in Sub-Seasonal Precipitation Predictability in the Northern Great Plains
by Carlos M. Carrillo and Francisco Muñoz-Arriola
Atmosphere 2024, 15(7), 858; https://doi.org/10.3390/atmos15070858 - 20 Jul 2024
Viewed by 820
Abstract
This study leverages the relationships between the Great Plains low-level jet (GP-LLJ) and the circumglobal teleconnection (CGT) to assess the enhancement of 30-day rainfall forecast in the Northern Great Plains (NGP). The assessment of 30-day simulated precipitation using the Climate Forecast System (CFS) [...] Read more.
This study leverages the relationships between the Great Plains low-level jet (GP-LLJ) and the circumglobal teleconnection (CGT) to assess the enhancement of 30-day rainfall forecast in the Northern Great Plains (NGP). The assessment of 30-day simulated precipitation using the Climate Forecast System (CFS) is contrasted with the North American Regional Reanalysis, searching for sources of precipitation predictability associated with extended wet and drought events. We analyze the 30-day sources of precipitation predictability using (1) the characterization of dominant statistical modes of variability of 900 mb winds associated with the GP-LLJ, (2) the large-scale atmospheric patterns based on 200 mb geopotential height (HGT), and (3) the use of GP-LLJ and CGT conditional probability distributions using a continuous correlation threshold approach to identify when and where the forecast of NGP precipitation occurs. Two factors contributing to the predictability of precipitation in the NGP are documented. We found that the association between GP-LLJ and CGT occurs at two different scales—the interdiurnal and the sub-seasonal, respectively. The CFS reforecast suggests that the ability to forecast sub-seasonal precipitation improves in response to the enhanced simulation of the GP-LLJ and CGT. Using these modes of climate variability could improve predictive frameworks for water resources management, governance, and water supply for agriculture. Full article
(This article belongs to the Special Issue Prediction and Modeling of Extreme Weather Events)
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11 pages, 7224 KiB  
Article
Connection between Winter East Asia Flow Patterns and Stratospheric Polar Vortex Anomalies
by Masakazu Taguchi
Atmosphere 2024, 15(7), 844; https://doi.org/10.3390/atmos15070844 - 17 Jul 2024
Viewed by 612
Abstract
Using a reanalysis dataset, this work investigates the possible connection of winter East Asia (EA) flow patterns to stratospheric polar vortex (SPV) anomalies. Cluster analysis is performed on the principal components of daily 500 hPa geopotential height fields to identify five distinct flow [...] Read more.
Using a reanalysis dataset, this work investigates the possible connection of winter East Asia (EA) flow patterns to stratospheric polar vortex (SPV) anomalies. Cluster analysis is performed on the principal components of daily 500 hPa geopotential height fields to identify five distinct flow patterns. SPV anomalies are considered in terms of the occurrence of major sudden stratospheric warmings (MSSWs). The results reveal that for the 15 days before the MSSWs, one of the five patterns occurs more frequently than usual, whereas another occurs less frequently. The former constructively interferes with the climatological EA trough in the troposphere and strengthens the planetary wave activity (heat flux) in the extratropical troposphere and stratosphere. It has a similar pattern in the 500 hPa height to the composite leading to the MSSWs, implying that such strengthening can contribute to the forcing of the MSSWs. The latter is in the opposite sense (destructive interference) and is disadvantageous before the MSSWs. Evidence of a stratospheric downward influence on the five flow patterns is relatively unclear. These results suggest a potential coupling between flow patterns or weather regimes in different regions through the SPV, as well as warrant further investigation of the downward influence on EA weather regimes. Full article
(This article belongs to the Section Meteorology)
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